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* drm: Update MST First Link Slot Information Based on Encoding FormatBhawanpreet Lakha2021-10-251-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 8b/10b encoding format requires to reserve the first slot for recording metadata. Real data transmission starts from the second slot, with a total of available 63 slots available. In 128b/132b encoding format, metadata is transmitted separately in LLCP packet before MTP. Real data transmission starts from the first slot, with a total of 64 slots available. v2: * Move total/start slots to mst_state, and copy it to mst_mgr in atomic_check v3: * Only keep the slot info on the mst_state * add a start_slot parameter to the payload function, to facilitate non atomic drivers (this is a temporary workaround and should be removed when we are moving out the non atomic driver helpers) v4: *fixed typo and formatting v5: (no functional changes) * Fixed formatting in drm_dp_mst_update_slots() * Reference mst_state instead of mst_state->mgr for debugging info Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com> Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com> [v5 nitpicks] Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211025223825.301703-3-lyude@redhat.com
* drm/dp_mst: Use kHz as link rate units when settig source max link caps at initNikola Cornij2021-05-271-4/+4
| | | | | | | | | | | | | | | | | | [why] Link rate in kHz is what is eventually required to calculate the link bandwidth, which makes kHz a more generic unit. This should also make forward-compatibility with new DP standards easier. [how] - Replace 'link rate DPCD code' with 'link rate in kHz' when used with drm_dp_mst_topology_mgr_init() - Add/remove related DPCD code conversion from/to kHz where applicable Signed-off-by: Nikola Cornij <nikola.cornij@amd.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210512210011.8425-2-nikola.cornij@amd.com
* drm/dp_mst: Use Extended Base Receiver Capability DPCD spaceNikola Cornij2021-04-291-1/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | [why] DP 1.4a spec mandates that if DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT is set, Extended Base Receiver Capability DPCD space must be used. Without doing that, the three DPCD values that differ will be wrong, leading to incorrect or limited functionality. MST link rate, for example, could have a lower value. Also, Synaptics quirk wouldn't work out well when Extended DPCD was not read, resulting in no DSC for such hubs. [how] Modify MST topology manager to use the values from Extended DPCD where applicable. To prevent regression on the sources that have a lower maximum link rate capability than MAX_LINK_RATE from Extended DPCD, have the drivers supply maximum lane count and rate at initialization time. This also reverts commit 2dcab875e763 ("Revert drm/dp_mst: Retrieve extended DPCD caps for topology manager"), brining the change back to the original commit ad44c03208e4 ("drm/dp_mst: Retrieve extended DPCD caps for topology manager"). Signed-off-by: Nikola Cornij <nikola.cornij@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210429221151.22020-2-nikola.cornij@amd.com
* drm/dp_mst: Pass drm_dp_mst_topology_mgr to drm_dp_get_vc_payload_bw()Lyude Paul2021-04-271-1/+2
| | | | | | | | | | | Since this is one of the few functions in drm_dp_mst_topology.c that doesn't have any way of getting access to a drm_device, let's pass the drm_dp_mst_topology_mgr down to this function so that it can use drm_dbg_kms(). Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210423184309.207645-14-lyude@redhat.com Reviewed-by: Dave Airlie <airlied@redhat.com>
* drm/dp/mst: Export drm_dp_get_vc_payload_bw()Imre Deak2021-02-021-0/+1
| | | | | | | | | | | | | | | | | | | | | This function will be needed by the next patch where the driver calculates the BW based on driver specific parameters, so export it. At the same time sanitize the function params, passing the more natural link rate instead of the encoding of the same rate. v2: - Fix function documentation. (Lyude) Cc: Lyude Paul <lyude@redhat.com> Cc: Ville Syrjala <ville.syrjala@intel.com> Cc: <stable@vger.kernel.org> Cc: dri-devel@lists.freedesktop.org Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210125173636.1733812-1-imre.deak@intel.com (cherry picked from commit a321fc2b4e60fc1b39517d26c8104351636a6062) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
* Merge drm/drm-next into drm-intel-next-queuedRodrigo Vivi2020-09-111-2/+1
|\ | | | | | | | | | | Sync drm-intel-gt-next here so we can have an unified fixes flow. Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
| * drm/i915/dp: Extract drm_dp_read_mst_cap()Lyude Paul2020-08-311-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just a tiny drive-by cleanup, we can consolidate i915's code for checking for MST support into a helper to be shared across drivers. v5: * Drop !!() * Move drm_dp_has_mst() out of header * Change name from drm_dp_has_mst() to drm_dp_read_mst_cap() Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Sean Paul <sean@poorly.run> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200826182456.322681-10-lyude@redhat.com
* | drm/mst: Add support for QUERY_STREAM_ENCRYPTION_STATUS MST sideband messageSean Paul2020-09-011-0/+44
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Used to query whether an MST stream is encrypted or not. Cc: Lyude Paul <lyude@redhat.com> Reviewed-by: Anshuman Gupta <anshuman.gupta@intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200218220242.107265-14-sean@poorly.run #v4 Link: https://patchwork.freedesktop.org/patch/msgid/20200305201236.152307-15-sean@poorly.run #v5 Link: https://patchwork.freedesktop.org/patch/msgid/20200429195502.39919-15-sean@poorly.run #v6 Link: https://patchwork.freedesktop.org/patch/msgid/20200623155907.22961-16-sean@poorly.run #v7 Link: https://patchwork.freedesktop.org/patch/msgid/20200818153910.27894-16-sean@poorly.run #v8 Changes in v4: -Added to the set Changes in v5: -None Changes in v6: -Use FIELD_PREP to generate request buffer bitfields (Lyude) -Add mst selftest and dump/decode_sideband_req for QSES (Lyude) Changes in v7: -None Changes in v8: -Reverse the parsing on the hdcp_*x_device_present bits and leave breadcrumb in case this is incorrect (Anshuman) Changes in v8.5: -s/DRM_DEBUG_KMS/drm_dbg_kms/ (Lyude) Signed-off-by: Ramalingam C <ramalingam.c@intel.com> Acked-by: Daniel Vetter <daniel@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20200819143133.46232-1-sean@poorly.run
* drm/dp_mst: Fix flushing the delayed port/mstb destroy workImre Deak2020-06-111-0/+8
| | | | | | | | | | | | | | | | | Atm, a pending delayed destroy work during module removal will be canceled, leaving behind MST ports, mstbs. Fix this by using a dedicated workqueue which will be drained of requeued items as well when destroying it. v2: - Check if wq is NULL before calling destroy_workqueue(). Cc: Lyude Paul <lyude@redhat.com> Cc: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200610134704.25270-1-imre.deak@intel.com
* drm/i915/dp_mst: Work around out-of-spec adapters filtering short pulsesImre Deak2020-06-111-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some TypeC -> native DP adapters, at least the Club 3D CAC-1557 adapter, incorrectly filter out HPD short pulses with a duration less than ~540 usec, leading to MST probe failures. According to the DP Standard 2.0 section 5.1.4: - DP sinks should generate short pulses in the 500 usec -> 1 msec range - DP sources should detect short pulses in the 250 usec -> 2 msec range According to the DP Alt Mode on TypeC Standard section 3.9.2, adapters should detect and forward short pulses according to how sources should detect them as specified in the DP Standard (250 usec -> 2 msec). Based on the above filtering out short pulses with a duration less than 540 usec is incorrect. To make such adapters work add support for a driver polling on MST inerrupt flags, and wire this up in the i915 driver. The sink can clear an interrupt it raised after 110 msec if the source doesn't respond, so use a 50 msec poll period to avoid missing an interrupt. Polling of the MST interrupt flags is explicitly allowed by the DP Standard. This fixes MST probe failures I saw using this adapter and a DELL U2515H monitor. v2: - Fix the wait event timeout for the no-poll case. v3 (Ville): - Fix the short pulse duration limits in the commit log prescribed by the DP Standard. - Add code comment explaining why/how polling is used. - Factor out a helper to schedule the port's hpd irq handler and move it to the rest of hotplug handlers. - Document the new MST callback. - s/update_hpd_irq_state/poll_hpd_irq/ Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200604184500.23730-2-imre.deak@intel.com
* drm/dp_mst: Kill the second sideband tx slot, save the worldLyude Paul2020-04-271-21/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While we support using both tx slots for sideband transmissions, it appears that DisplayPort devices in the field didn't end up doing a very good job of supporting it. From section 5.2.1 of the DP 2.0 specification: There are MST Sink/Branch devices in the field that do not handle interleaved message transactions. To facilitate message transaction handling by downstream devices, an MST Source device shall generate message transactions in an atomic manner (i.e., the MST Source device shall not concurrently interleave multiple message transactions). Therefore, an MST Source device shall clear the Message_Sequence_No value in the Sideband_MSG_Header to 0. This might come as a bit of a surprise since the vast majority of hubs will support using both tx slots even if they don't support interleaved message transactions, and we've also been using both tx slots since MST was introduced into the kernel. However, there is one device we've had trouble getting working consistently with MST for so long that we actually assumed it was just broken: the infamous Dell P2415Qb. Previously this monitor would appear to work sometimes, but in most situations would end up timing out LINK_ADDRESS messages almost at random until you power cycled the whole display. After reading section 5.2.1 in the DP 2.0 spec, some closer investigation into this infamous display revealed it was only ever timing out on sideband messages in the second TX slot. Sure enough, avoiding the second TX slot has suddenly made this monitor function perfectly for the first time in five years. And since they explicitly mention this in the specification, I doubt this is the only monitor out there with this issue. This might even explain explain the seemingly harmless garbage sideband responses we would occasionally see with MST hubs! So - rewrite our sideband TX handlers to only support one TX slot. In order to simplify our sideband handling now that we don't support transmitting to multiple MSTBs at once, we also move all state tracking for down replies from mstbs to the topology manager. Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: ad7f8a1f9ced ("drm/helper: add Displayport multi-stream helper (v0.6)") Cc: Sean Paul <sean@poorly.run> Cc: "Lin, Wayne" <Wayne.Lin@amd.com> Cc: <stable@vger.kernel.org> # v3.17+ Reviewed-by: Sean Paul <sean@poorly.run> Link: https://patchwork.freedesktop.org/patch/msgid/20200424181308.770749-1-lyude@redhat.com
* Revert "drm/dp_mst: Remove single tx msg restriction."Lyude Paul2020-04-231-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 6bb0942e8f46863a745489cce27efe5be2a3885e. Unfortunately it would appear that the rumors we've heard of sideband message interleaving not being very well supported are true. On the Lenovo ThinkPad Thunderbolt 3 dock that I have, interleaved messages appear to just get dropped: [drm:drm_dp_mst_wait_tx_reply [drm_kms_helper]] timedout msg send 00000000571ddfd0 2 1 [dp_mst] txmsg cur_offset=2 cur_len=2 seqno=1 state=SENT path_msg=1 dst=00 [dp_mst] type=ENUM_PATH_RESOURCES contents: [dp_mst] port=2 DP descriptor for this hub: OUI 90-cc-24 dev-ID SYNA3 HW-rev 1.0 SW-rev 3.12 quirks 0x0008 It would seem like as well that this is a somewhat well known issue in the field. From section 5.4.2 of the DisplayPort 2.0 specification: There are MST Sink/Branch devices in the field that do not handle interleaved message transactions. To facilitate message transaction handling by downstream devices, an MST Source device shall generate message transactions in an atomic manner (i.e., the MST Source device shall not concurrently interleave multiple message transactions). Therefore, an MST Source device shall clear the Message_Sequence_No value in the Sideband_MSG_Header to 0. MST Source devices that support field policy updates by way of software should update the policy to forego the generation of interleaved message transactions. This is a bit disappointing, as features like HDCP require that we send a sideband request every ~2 seconds for each active stream. However, there isn't really anything in the specification that allows us to accurately probe for interleaved messages. If it ends up being that we -really- need this in the future, we might be able to whitelist hubs where interleaving is known to work-or maybe try some sort of heuristics. But for now, let's just play it safe and not use it. Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: 6bb0942e8f46 ("drm/dp_mst: Remove single tx msg restriction.") Cc: Wayne Lin <Wayne.Lin@amd.com> Cc: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200423164225.680178-1-lyude@redhat.com Reviewed-by: Sean Paul <sean@poorly.run>
* Merge drm/drm-next into drm-misc-nextThomas Zimmermann2020-04-171-2/+2
|\ | | | | | | | | | | Backmerging required to pull topic/phy-compliance. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
| * Merge v5.6 into drm-nextDave Airlie2020-03-311-2/+2
| |\ | | | | | | | | | | | | | | | | | | msm needed rc6, so I just went and merged release (msm has been in drm-next outside of this tree) Signed-off-by: Dave Airlie <airlied@redhat.com>
| | * drm/dp_mst: Use full_pbn instead of available_pbn for bandwidth checksLyude Paul2020-03-121-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | DisplayPort specifications are fun. For a while, it's been really unclear to us what available_pbn actually does. There's a somewhat vague explanation in the DisplayPort spec (starting from 1.2) that partially explains it: The minimum payload bandwidth number supported by the path. Each node updates this number with its available payload bandwidth number if its payload bandwidth number is less than that in the Message Transaction reply. So, it sounds like available_pbn represents the smallest link rate in use between the source and the branch device. Cool, so full_pbn is just the highest possible PBN that the branch device supports right? Well, we assumed that for quite a while until Sean Paul noticed that on some MST hubs, available_pbn will actually get set to 0 whenever there's any active payloads on the respective branch device. This caused quite a bit of confusion since clearing the payload ID table would end up fixing the available_pbn value. So, we just went with that until commit cd82d82cbc04 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check") started breaking people's setups due to us getting erroneous available_pbn values. So, we did some more digging and got confused until we finally looked at the definition for full_pbn: The bandwidth of the link at the trained link rate and lane count between the DP Source device and the DP Sink device with no time slots allocated to VC Payloads, represented as a Payload Bandwidth Number. As with the Available_Payload_Bandwidth_Number, this number is determined by the link with the lowest lane count and link rate. That's what we get for not reading specs closely enough, hehe. So, since full_pbn is definitely what we want for doing bandwidth restriction checks - let's start using that instead and ignore available_pbn entirely. Signed-off-by: Lyude Paul <lyude@redhat.com> Fixes: cd82d82cbc04 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check") Cc: Mikita Lipski <mikita.lipski@amd.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Sean Paul <sean@poorly.run> Reviewed-by: Mikita Lipski <mikita.lipski@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200306234623.547525-3-lyude@redhat.com Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Tested-by: Hans de Goede <hdegoede@redhat.com>
* | | drm/dp_mst: Remove drm_dp_mst_has_audio()Lyude Paul2020-04-071-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drive-by fix I noticed the other day - drm_dp_mst_has_audio() only ever made sense back when we still had to validate ports before accessing them in order to (attempt to) avoid NULL dereferences. Since we have proper reference counting that guarantees we always can safely access the MST port, there's no use in keeping this function around as all it does is validate the port pointer before checking the audio status. Note - drm_dp_mst_port->has_audio is technically protected by drm_device->mode_config.connection_mutex, since it's only ever updated from drm_dp_mst_get_edid(). Additionally, we change the declaration for port in struct intel_connector to be properly typed, so we can directly access it. Changes since v1: * Change type of intel_connector->port in a separate patch - Sean Paul Cc: "Lee, Shawn C" <shawn.c.lee@intel.com> Reviewed-by: Sean Paul <sean@poorly.run> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200406200646.1263435-2-lyude@redhat.com
* | | drm/dp_mst: Remove drm_dp_mst_topology_cbs.destroy_connectorLyude Paul2020-04-031-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we've removed the last user of this callback, get rid of it and drm_dp_destroy_connector(). Signed-off-by: Lyude Paul <lyude@redhat.com> Cc: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200331205740.135525-5-lyude@redhat.com Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
* | | drm/dp_mst: add kernel-doc for drm_dp_mst_port.fec_capableSam Ravnborg2020-03-301-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix kernel-doc warnings for drm_dp_mst_port.fec_capable. This fixed the following warning: drm_dp_mst_helper.h:162: warning: Function parameter or member 'fec_capable' not described in 'drm_dp_mst_port' Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Cc: David Francis <David.Francis@amd.com> Cc: Lyude Paul <lyude@redhat.com> Cc: Harry Wentland <harry.wentland@amd.com> Cc: Mikita Lipski <mikita.lipski@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <mripard@kernel.org> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> [Wrapped commit msg + s/network/topology] Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200328132025.19910-6-sam@ravnborg.org
* | | drm/dp_mst: Remove single tx msg restriction.Sean Paul2020-03-271-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we can support multiple simultaneous replies, remove the restrictions placed on sending new tx msgs. This patch essentially just reverts commit 5a64967a2f3b ("drm/dp_mst: Have DP_Tx send one msg at a time") now that the problem is solved in a different way. Cc: Wayne Lin <Wayne.Lin@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Wayne Lin <waynelin@amd.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200213211523.156998-4-sean@poorly.run
* | | drm/mst: Support simultaneous down repliesSean Paul2020-03-271-29/+30
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we have one down reply message servicing the mst manager, so we need to serialize all tx msgs to ensure we only have one message in flight at a time. For obvious reasons this is suboptimal (but less suboptimal than the free-for-all we had before serialization). This patch removes the single down_rep_recv message from manager and adds 2 replies in the branch structure. The 2 replies mirrors the tx_slots which we use to rate-limit outgoing messages and correspond to seqno in the packet headers. Cc: Wayne Lin <Wayne.Lin@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Wayne Lin <waynelin@amd.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20200213211523.156998-3-sean@poorly.run
* | drm/dp_mst: Convert drm_dp_mst_topology_mgr.is_waiting_for_dwn_reply to bitfieldLyude Paul2020-03-131-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | Small nitpick that I noticed a second ago - we can save some space in the struct by making this a bitfield and sticking it with the rest of the bitfields. Also, some small cleanup to the kdocs for this member. There should be no functional changes in this patch. Signed-off-by: Lyude Paul <lyude@redhat.com> Cc: Wayne Lin <Wayne.Lin@amd.com> Reviewed-by: Wayne Lin <Wayne.Lin@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200122194846.16025-1-lyude@redhat.com
* | drm/dp_mst: Remove register_connector callbackPankaj Bharadiya2020-03-111-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | Now drm_dp_mst_topology_cbs.register_connector callback is not getting used anymore hence remove it. Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com> Suggested-by: Emil Velikov <emil.velikov@collabora.com> Suggested-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200307083023.76498-4-pankaj.laxminarayan.bharadiya@intel.com Reviewed-by: Lyude Paul <lyude@redhat.com>
* | Merge v5.6-rc2 into drm-misc-nextMaxime Ripard2020-02-171-3/+23
|\| | | | | | | | | | | | | Lyude needs some patches in 5.6-rc2 and we didn't bring drm-misc-next forward yet, so it looks like a good occasion. Signed-off-by: Maxime Ripard <maxime@cerno.tech>
| * Backmerge v5.5-rc7 into drm-nextDave Airlie2020-01-201-0/+6
| |\ | | | | | | | | | | | | | | | msm needs 5.5-rc4, go to the latest. Signed-off-by: Dave Airlie <airlied@redhat.com>
| | * drm/dp_mst: Have DP_Tx send one msg at a timeWayne Lin2020-01-151-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [Why] Noticed this while testing MST with the 4 ports MST hub from StarTech.com. Sometimes can't light up monitors normally and get the error message as 'sideband msg build failed'. Look into aux transactions, found out that source sometimes will send out another down request before receiving the down reply of the previous down request. On the other hand, in drm_dp_get_one_sb_msg(), current code doesn't handle the interleaved replies case. Hence, source can't build up message completely and can't light up monitors. [How] For good compatibility, enforce source to send out one down request at a time. Add a flag, is_waiting_for_dwn_reply, to determine if the source can send out a down request immediately or not. - Check the flag before calling process_single_down_tx_qlock to send out a msg - Set the flag when successfully send out a down request - Clear the flag when successfully build up a down reply - Clear the flag when find erros during sending out a down request - Clear the flag when find errors during building up a down reply - Clear the flag when timeout occurs during waiting for a down reply - Use drm_dp_mst_kick_tx() to try to send another down request in queue at the end of drm_dp_mst_wait_tx_reply() (attempt to send out messages in queue when errors occur) Cc: Lyude Paul <lyude@redhat.com> Signed-off-by: Wayne Lin <Wayne.Lin@amd.com> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200113093649.11755-1-Wayne.Lin@amd.com
| * | drm/dp_mst: Add helper to trigger modeset on affected DSC MST CRTCsMikita Lipski2020-01-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [why] Whenever a connector on an MST network is changed or undergoes a modeset, the DSC configs for each stream on that topology will be recalculated. This can change their required bandwidth, requiring a full reprogramming, as though a modeset was performed, even if that stream did not change timing. [how] Adding helper to trigger modesets on MST DSC connectors by setting mode_changed flag on CRTCs in the same topology as affected connector v2: use drm_dp_mst_dsc_aux_for_port function to verify if the port is DSC capable v3: - added _must_check attribute - removed topology manager check - fix typos and indentations Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| * | drm/dp_mst: Add branch bandwidth validation to MST atomic checkMikita Lipski2020-01-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [why] Adding PBN attribute to drm_dp_vcpi_allocation structure to keep track of how much bandwidth each Port requires. Adding drm_dp_mst_atomic_check_bw_limit to verify that state's bandwidth needs doesn't exceed available bandwidth. The funtion is called in drm_dp_mst_atomic_check after drm_dp_mst_atomic_check_topology_state to fully verify that the proposed topology is supported. v2: Fixing some typos and indenting v3: Return correct error enums if no bw space available Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| * | drm/dp_mst: Add DSC enablement helpers to DRMMikita Lipski2020-01-091-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding a helper function to be called by drivers outside of DRM to enable DSC on the MST ports. Function is called to recalculate VCPI allocation if DSC is enabled and raise the DSC flag to enable. In case of disabling DSC the flag is set to false and recalculation of VCPI slots is expected to be done in encoder's atomic_check. v2: squash separate functions into one and call it per port v3: Fix comment typos Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| * | drm/dp_mst: Manually overwrite PBN divider for calculating timeslotsMikita Lipski2020-01-091-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [why] For DSC case we cannot use topology manager's PBN divider variable. The default divider does not take FEC into account. Therefore the driver has to calculate its own divider based on the link rate and lane count its handling, as it is hw specific. [how] Pass pbn_div as an argument, which is used if its more than zero, otherwise default topology manager's pbn_div will be used. Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| * | drm/dp_mst: Add helpers for MST DSC and virtual DPCD auxDavid Francis2020-01-091-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add drm_dp_mst_dsc_aux_for_port. To enable DSC, the DSC_ENABLED register might have to be written on the leaf port's DPCD, its parent's DPCD, or the MST manager's DPCD. This function finds the correct aux for the job. As part of this, add drm_dp_mst_is_virtual_dpcd. Virtual DPCD is a DP feature new in DP v1.4, which exposes certain DPCD registers on virtual ports. v2: Remember to unlock mutex on all paths v3: Refactor to match coding style and increase brevity v4: - Check DSC capable MST sink connected directly to the device. - Check branch's port_parent to be set Cc: Lyude Paul <lyude@redhat.com> Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com> Signed-off-by: David Francis <David.Francis@amd.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| * | drm/dp_mst: Parse FEC capability on MST portsDavid Francis2020-01-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As of DP1.4, ENUM_PATH_RESOURCES returns a bit indicating if FEC can be supported up to that point in the MST network. The bit is the first byte of the ENUM_PATH_RESOURCES ack reply, bottom-most bit (refer to section 2.11.9.4 of DP standard, v1.4) That value is needed for FEC and DSC support Store it on drm_dp_mst_port Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: David Francis <David.Francis@amd.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| * | drm/dp_mst: Add PBN calculation for DSC modesDavid Francis2020-01-091-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With DSC, bpp can be fractional in multiples of 1/16. Change drm_dp_calc_pbn_mode to reflect this, adding a new parameter bool dsc. When this parameter is true, treat the bpp parameter as having units not of bits per pixel, but 1/16 of a bit per pixel v2: Don't add separate function for this v3: In the equation divide bpp by 16 as it is expected not to leave any remainder v4: Added DSC test parameters for selftest Reviewed-by: Manasi Navare <manasi.d.navare@intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: David Francis <David.Francis@amd.com> Signed-off-by: Mikita Lipski <mikita.lipski@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
* | | drm/dp_mst: Mention max_payloads in proposed_vcpis/payloads docsLyude Paul2020-01-221-2/+4
|/ / | | | | | | | | | | | | | | | | | | Mention that the size of these two structs is determined by max_payloads. Suggested by Ville Syrjälä. Signed-off-by: Lyude Paul <lyude@redhat.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200122194321.14953-2-lyude@redhat.com
* | Merge tag 'drm-misc-next-2019-12-16' of ↵Daniel Vetter2019-12-171-2/+10
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://anongit.freedesktop.org/drm/drm-misc into drm-next drm-misc-next for v5.6: UAPI Changes: - Add support for DMA-BUF HEAPS. Cross-subsystem Changes: - mipi dsi definition updates, pulled into drm-intel as well. - Add lockdep annotations for dma_resv vs mmap_sem and fs_reclaim. - Remove support for dma-buf kmap/kunmap. - Constify fb_ops in all fbdev drivers, including drm drivers and drm-core, and media as well. Core Changes: - Small cleanups to ttm. - Fix SCDC definition. - Assorted cleanups to core. - Add todo to remove load/unload hooks, and use generic fbdev emulation. - Assorted documentation updates. - Use blocking ww lock in ttm fault handler. - Remove drm_fb_helper_fbdev_setup/teardown. - Warning fixes with W=1 for atomic. - Use drm_debug_enabled() instead of drm_debug flag testing in various drivers. - Fallback to nontiled mode in fbdev emulation when not all tiles are present. (Later on reverted) - Various kconfig indentation fixes in core and drivers. - Fix freeing transactions in dp-mst correctly. - Sean Paul is steping down as core maintainer. :-( - Add lockdep annotations for atomic locks vs dma-resv. - Prevent use-after-free for a bad job in drm_scheduler. - Fill out all block sizes in the P01x and P210 definitions. - Avoid division by zero in drm/rect, and fix bounds. - Add drm/rect selftests. - Add aspect ratio and alternate clocks for HDMI 4k modes. - Add todo for drm_framebuffer_funcs and fb_create cleanup. - Drop DRM_AUTH for prime import/export ioctls. - Clear DP-MST payload id tables downstream when initializating. - Fix for DSC throughput definition. - Add extra FEC definitions. - Fix fake offset in drm_gem_object_funs.mmap. - Stop using encoder->bridge in core directly - Handle bridge chaining slightly better. - Add backlight support to drm/panel, and use it in many panel drivers. - Increase max number of y420 modes from 128 to 256, as preparation to add the new modes. Driver Changes: - Small fixes all over. - Fix documentation in vkms. - Fix mmap_sem vs dma_resv in nouveau. - Small cleanup in komeda. - Add page flip support in gma500 for psb/cdv. - Add ddc symlink in the connector sysfs directory for many drivers. - Add support for analogic an6345, and fix small bugs in it. - Add atomic modesetting support to ast. - Fix radeon fault handler VMA race. - Switch udl to use generic shmem helpers. - Unconditional vblank handling for mcde. - Miscellaneous fixes to mcde. - Tweak debug output from komeda using debugfs. - Add gamma and color transform support to komeda for DOU-IPS. - Add support for sony acx424AKP panel. - Various small cleanups to gma500. - Use generic fbdev emulation in udl, and replace udl_framebuffer with generic implementation. - Add support for Logic PD Type 28 panel. - Use drm_panel_* wrapper functions in exynos/tegra/msm. - Add devicetree bindings for generic DSI panels. - Don't include drm_pci.h directly in many drivers. - Add support for begin/end_cpu_access in udmabuf. - Stop using drm_get_pci_dev in gma500 and mga200. - Fixes to UDL damage handling, and use dma_buf_begin/end_cpu_access. - Add devfreq thermal support to panfrost. - Fix hotplug with daisy chained monitors by removing VCPI when disabling topology manager. - meson: Add support for OSD1 plane AFBC commit. - Stop displaying garbage when toggling ast primary plane on/off. - More cleanups and fixes to UDL. - Add D32 suport to komeda. - Remove globle copy of drm_dev in gma500. - Add support for Boe Himax8279d MIPI-DSI LCD panel. - Add support for ingenic JZ4770 panel. - Small null pointer deference fix in ingenic. - Remove support for the special tfp420 driver, as there is a generic way to do it. Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/ba73535a-9334-5302-2e1f-5208bd7390bd@linux.intel.com
| * drm/dp_mst: Clear all payload id tables downstream when initializingSean Paul2019-12-051-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It seems that on certain MST hubs, namely the CableMatters USB-C 2x DP hub, using the DP_PAYLOAD_ALLOCATE_SET and DP_PAYLOAD_TABLE_UPDATE_STATUS register ranges to clear any pre-existing payload allocations on the hub isn't always enough to reset things if the source device has been reset unexpectedly. Or at least, that's the current running theory. The precise behavior appears to be that when the source device gets reset unexpectedly, the hub begins reporting an available_pbn value of 0 for all of its ports. This is a bit inconsistent with the our theory, since this seems to happen even if previously set PBN allocations should have resulted in a non-zero available_pbn value. So, it's possible that something else may be going on here. Strangely though, sending a CLEAR_PAYLOAD_ID_TABLE broadcast request when initializing the MST topology seems to bring things into working order and make available_pbn work again. Since this is a pretty safe solution, let's go ahead and implement it. Changes since v1: * Change indenting on drm_dp_send_clear_payload_id_table() prototype * Remove some braces in drm_dp_send_clear_payload_id_table() * Reorganize some variable declarations in drm_dp_send_clear_payload_id_table() * Don't forget to handle DP_CLEAR_PAYLOAD_ID_TABLE in drm_dp_sideband_parse_reply() * Move drm_dp_send_clear_payload_id_table() call into drm_dp_mst_link_probe_work(), since we can't send sideband messages while under lock in drm_dp_mst_topology_mgr_set_mst() * Change commit message Acked-by: Daniel Vetter <daniel@ffwll.ch> Signed-off-by: Sean Paul <seanpaul@chromium.org> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190829000944.20722-1-lyude@redhat.com
* | drm/dp_mst: Add topology ref history tracking for debuggingLyude Paul2019-10-241-0/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For very subtle mistakes with topology refs, it can be rather difficult to trace them down with the debugging info that we already have. I had one such issue recently while trying to implement suspend/resume reprobing for MST, and ended up coming up with this. Inspired by Chris Wilson's wakeref tracking for i915, this adds a very similar feature to the DP MST helpers, which allows for partial tracking of topology refs for both ports and branch devices. This is a lot less advanced then wakeref tracking: we merely keep a count of all of the spots where a topology ref has been grabbed or dropped, then dump out that history in chronological order when a port or branch device's topology refcount reaches 0. So far, I've found this incredibly useful for debugging topology refcount errors. Since this has the potential to be somewhat slow and loud, we add an expert kernel config option to enable or disable this feature, CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS. Changes since v1: * Don't forget to destroy topology_ref_history_lock Changes since v4: * Correct order of kref_put()/topology_ref_history_unlock - we can't unlock the history after kref_put() since the memory might have been freed by that point * Don't print message on allocation error failures, the kernel already does this for us Changes since v5: * Get rid of some leftover usages of %px * Remove a leftover empty return; statement Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Sean Paul <sean@poorly.run> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-15-lyude@redhat.com
* | drm/dp_mst: Add basic topology reprobing when resumingLyude Paul2019-10-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Finally! For a very long time, our MST helpers have had one very annoying issue: They don't know how to reprobe the topology state when coming out of suspend. This means that if a user has a machine connected to an MST topology and decides to suspend their machine, we lose all topology changes that happened during that period. That can be a big problem if the machine was connected to a different topology on the same port before resuming, as we won't bother reprobing any of the ports and likely cause the user's monitors not to come back up as expected. So, we start fixing this by teaching our MST helpers how to reprobe the link addresses of each connected topology when resuming. As it turns out, the behavior that we want here is identical to the behavior we want when initially probing a newly connected MST topology, with a couple of important differences: - We need to be more careful about handling the potential races between events from the MST hub that could change the topology state as we're performing the link address reprobe - We need to be more careful about handling unlikely state changes on ports - such as an input port turning into an output port, something that would be far more likely to happen in situations like the MST hub we're connected to being changed while we're suspend Both of which have been solved by previous commits. That leaves one requirement: - We need to prune any MST ports in our in-memory topology state that were present when suspending, but have not appeared in the post-resume link address response from their parent branch device Which we can now handle in this commit by modifying drm_dp_send_link_address(). We then introduce suspend/resume reprobing by introducing drm_dp_mst_topology_mgr_invalidate_mstb(), which we call in drm_dp_mst_topology_mgr_suspend() to traverse the in-memory topology state to indicate that each mstb needs it's link address resent and PBN resources reprobed. On resume, we start back up &mgr->work and have it reprobe the topology in the same way we would on a hotplug, removing any leftover ports that no longer appear in the topology state. Changes since v4: * Split indenting changes in drm_dp_mst_topology_mgr_resume() into a separate patch * Only fire hotplugs when something has actually changed after a link address probe * Don't try to change port->connector at all on ports, just throw out ports that need their connectors removed to make things easier. Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Sean Paul <sean@poorly.run> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-14-lyude@redhat.com
* | drm/dp_mst: Protect drm_dp_mst_port members with lockingLyude Paul2019-10-241-12/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a complicated one. Essentially, there's currently a problem in the MST core that hasn't really caused any issues that we're aware of (emphasis on "that we're aware of"): locking. When we go through and probe the link addresses and path resources in a topology, we hold no locks when updating ports with said information. The members I'm referring to in particular are: - ldps - ddps - mcs - pdt - dpcd_rev - num_sdp_streams - num_sdp_stream_sinks - available_pbn - input - connector Now that we're handling UP requests asynchronously and will be using some of the struct members mentioned above in atomic modesetting in the future for features such as PBN validation, this is going to become a lot more important. As well, the next few commits that prepare us for and introduce suspend/resume reprobing will also need clear locking in order to prevent from additional racing hilarities that we never could have hit in the past. So, let's solve this issue by using &mgr->base.lock, the modesetting lock which currently only protects &mgr->base.state. This works perfectly because it allows us to avoid blocking connection_mutex unnecessarily, and we can grab this in connector detection paths since it's a ww mutex. We start by having drm_dp_mst_handle_up_req() hold this when updating ports. For drm_dp_mst_handle_link_address_port() things are a bit more complicated. As I've learned the hard way, we can grab &mgr->lock.base for everything except for port->connector. See, our normal driver probing paths end up generating this rather obvious lockdep chain: &drm->mode_config.mutex -> crtc_ww_class_mutex/crtc_ww_class_acquire -> &connector->mutex However, sysfs grabs &drm->mode_config.mutex in order to protect itself from connector state changing under it. Because this entails grabbing kn->count, e.g. the lock that the kernel provides for protecting sysfs contexts, we end up grabbing kn->count followed by &drm->mode_config.mutex. This ends up creating an extremely rude chain: &kn->count -> &drm->mode_config.mutex -> crtc_ww_class_mutex/crtc_ww_class_acquire -> &connector->mutex I mean, look at that thing! It's just evil!!! This gross thing ends up making any calls to drm_connector_register()/drm_connector_unregister() impossible when holding any kind of modesetting lock. This is annoying because ideally, we always want to ensure that drm_dp_mst_port->connector never changes when doing an atomic commit or check that would affect the atomic topology state so that it can reliably and easily be used from future DRM DP MST helpers to assist with tasks such as scanning through the current VCPI allocations and adding connectors which need to have their allocations updated in response to a bandwidth change or the like. Being able to hold &mgr->base.lock throughout the entire link probe process would have been _great_, since we could prevent userspace from ever seeing any states in-between individual port changes and as a result likely end up with a much faster probe and more consistent results from said probes. But without some rework of how we handle connector probing in sysfs it's not at all currently possible. In the future, maybe we can try using the sysfs locks to protect updates to connector probing state and fix this mess. So for now, to protect everything other than port->connector under &mgr->base.lock and ensure that we still have the guarantee that atomic check/commit contexts will never see port->connector change we use a silly trick. See: port->connector only needs to change in order to ensure that input ports (see the MST spec) never have a ghost connector associated with them. But, there's nothing stopping us from simply throwing the entire port out and creating a new one in order to maintain that requirement while still keeping port->connector consistent across the lifetime of the port in atomic check/commit contexts. For all intended purposes this works fine, as we validate ports in any contexts we care about before using them and as such will end up reporting the connector as disconnected until it's port's destruction finalizes. So, we just do that in cases where we detect port->input has transitioned from true->false. We don't need to worry about the other direction, since a port without a connector isn't visible to userspace and as such doesn't need to be protected by &mgr->base.lock until we finish registering a connector for it. For updating members of drm_dp_mst_port other than port->connector, we simply grab &mgr->base.lock in drm_dp_mst_link_probe_work() for already registered ports, update said members and drop the lock before potentially registering a connector and probing the link address of it's children. Finally, we modify drm_dp_mst_detect_port() to take a modesetting lock acquisition context in order to acquire &mgr->base.lock under &connection_mutex and convert all it's users over to using the .detect_ctx probe hooks. With that, we finally have well defined locking. Changes since v4: * Get rid of port->mutex, stop using connection_mutex and just use our own modesetting lock - mgr->base.lock. Also, add a probe_lock that comes before this patch. * Just throw out ports that get changed from an output to an input, and replace them with new ports. This lets us ensure that modesetting contexts never see port->connector go from having a connector to being NULL. * Write an extremely detailed explanation of what problems this is trying to fix, since there's a _lot_ of context here and I honestly forgot some of it myself a couple times. * Don't grab mgr->lock when reading port->mstb in drm_dp_mst_handle_link_address_port(). It's not needed. Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Sean Paul <sean@poorly.run> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-7-lyude@redhat.com
* | drm/dp_mst: Add probe_lockLyude Paul2019-10-241-4/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, MST lacks locking in a lot of places that really should have some sort of locking. Hotplugging and link address code paths are some of the offenders here, as there is actually nothing preventing us from running a link address probe while at the same time handling a connection status update request - something that's likely always been possible but never seen in the wild because hotplugging has been broken for ages now (with the exception of amdgpu, for reasons I don't think are worth digging into very far). Note: I'm going to start using the term "in-memory topology layout" here to refer to drm_dp_mst_port->mstb and drm_dp_mst_branch->ports. Locking in these places is a little tougher then it looks though. Generally we protect anything having to do with the in-memory topology layout under &mgr->lock. But this becomes nearly impossible to do from the context of link address probes due to the fact that &mgr->lock is usually grabbed under random various modesetting locks, meaning that there's no way we can just invert the &mgr->lock order and keep it locked throughout the whole process of updating the topology. Luckily there are only two workers which can modify the in-memory topology layout: drm_dp_mst_up_req_work() and drm_dp_mst_link_probe_work(), meaning as long as we prevent these two workers from traveling the topology layout in parallel with the intent of updating it we don't need to worry about grabbing &mgr->lock in these workers for reads. We only need to grab &mgr->lock in these workers for writes, so that readers outside these two workers are still protected from the topology layout changing beneath them. So, add the new &mgr->probe_lock and use it in both drm_dp_mst_link_probe_work() and drm_dp_mst_up_req_work(). Additionally, add some more detailed explanations for how this locking is intended to work to drm_dp_mst_port->mstb and drm_dp_mst_branch->ports. Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Sean Paul <sean@poorly.run> Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-6-lyude@redhat.com
* | drm/dp_mst: Handle UP requests asynchronouslyLyude Paul2019-10-241-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Once upon a time, hotplugging devices on MST branches actually worked in DRM. Now, it only works in amdgpu (likely because of how it's hotplug handlers are implemented). On both i915 and nouveau, hotplug notifications from MST branches are noticed - but trying to respond to them causes messaging timeouts and causes the whole topology state to go out of sync with reality, usually resulting in the user needing to replug the entire topology in hopes that it actually fixes things. The reason for this is because the way we currently handle UP requests in MST is completely bogus. drm_dp_mst_handle_up_req() is called from drm_dp_mst_hpd_irq(), which is usually called from the driver's hotplug handler. Because we handle sending the hotplug event from this function, we actually cause the driver's hotplug handler (and in turn, all sideband transactions) to block on drm_device->mode_config.connection_mutex. This makes it impossible to send any sideband messages from the driver's connector probing functions, resulting in the aforementioned sideband message timeout. There's even more problems with this beyond breaking hotplugging on MST branch devices. It also makes it almost impossible to protect drm_dp_mst_port struct members under a lock because we then have to worry about dealing with all of the lock dependency issues that ensue. So, let's finally actually fix this issue by handling the processing of up requests asyncronously. This way we can send sideband messages from most contexts without having to deal with getting blocked if we hold connection_mutex. This also fixes MST branch device hotplugging on i915, finally! Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Sean Paul <sean@poorly.run> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-5-lyude@redhat.com
* | drm/dp_mst: Refactor pdt setup/teardown, add more lockingLyude Paul2019-10-241-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since we're going to be implementing suspend/resume reprobing very soon, we need to make sure we are extra careful to ensure that our locking actually protects the topology state where we expect it to. Turns out this isn't the case with drm_dp_port_setup_pdt() and drm_dp_port_teardown_pdt(), both of which change port->mstb without grabbing &mgr->lock. Additionally, since most callers of these functions are just using it to teardown the port's previous PDT and setup a new one we can simplify things a bit and combine drm_dp_port_setup_pdt() and drm_dp_port_teardown_pdt() into a single function: drm_dp_port_set_pdt(). This function also handles actually ensuring that we grab the correct locks when we need to modify port->mstb. Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Sean Paul <sean@poorly.run> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-4-lyude@redhat.com
* | drm/dp_mst: Destroy MSTBs asynchronouslyLyude Paul2019-10-241-7/+19
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reprobing an MST topology during resume, we have to account for the fact that while we were suspended it's possible that mstbs may have been removed from any ports in the topology. Since iterating downwards in the topology requires that we hold &mgr->lock, destroying MSTBs from this context would result in attempting to lock &mgr->lock a second time and deadlocking. So, fix this by first moving destruction of MSTBs into destroy_connector_work, then rename destroy_connector_work and friends to reflect that they now destroy both ports and mstbs. Note that even though this means that MSTBs will still be accessible for a short period of time between their removal from the topology and delayed destruction, we are still protected against referencing a MSTB with a refcount of 0 since we use kref_get_unless_zero() in most places. Changes since v1: * s/destroy_connector_list/destroy_port_list/ s/connector_destroy_lock/delayed_destroy_lock/ s/connector_destroy_work/delayed_destroy_work/ s/drm_dp_finish_destroy_branch_device/drm_dp_delayed_destroy_mstb/ s/drm_dp_finish_destroy_port/drm_dp_delayed_destroy_port/ - danvet * Use two loops in drm_dp_delayed_destroy_work() - danvet * Better explain why we need to do this - danvet * Use cancel_work_sync() instead of flush_work() - flush_work() doesn't account for work requeing Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel@ffwll.ch> Reviewed-by: Sean Paul <sean@poorly.run> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-2-lyude@redhat.com
* drm/dp_mst: Remove lies in {up, down}_rep_recv documentationLyude Paul2019-09-251-6/+2
| | | | | | | | | | | | | | These are most certainly accessed from far more than the mgr work. In fact, up_req_recv is -only- ever accessed from outside the mgr work. Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Sean Paul <sean@poorly.run> Link: https://patchwork.freedesktop.org/patch/msgid/20190903204645.25487-19-lyude@redhat.com
* drm/dp_mst: Add sideband down request tracing + selftestsLyude Paul2019-09-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unfortunately the DP MST helpers do not have much in the way of debugging utilities. So, let's add some! This adds basic debugging output for down sideband requests that we send from the driver, so that we can actually discern what's happening when sideband requests timeout. Since there wasn't really a good way of testing that any of this worked, I ended up writing simple selftests that lightly test sideband message encoding and decoding as well. Enjoy! Changes since v1: * Clean up DO_TEST() and sideband_msg_req_encode_decode() - danvet * Get rid of pr_fmt(), just define a prefix string instead and use drm_printf() * Check highest bit of VCPI in drm_dp_decode_sideband_req() - danvet * Make the switch case order between drm_dp_decode_sideband_req() and drm_dp_encode_sideband_req() the same - danvet * Only check DRM_UT_DP - danvet * Clean up sideband_msg_req_equal() from selftests a bit, and add comments explaining why we can't just use memcmp - danvet Cc: Juston Li <juston.li@intel.com> Cc: Imre Deak <imre.deak@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Harry Wentland <hwentlan@amd.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190903204645.25487-8-lyude@redhat.com
* drm: mst: Fix query_payload ack reply structSean Paul2019-08-291-1/+1
| | | | | | | | | | | | | | | | | | | | Spec says[1] Allocated_PBN is 16 bits [1]- DisplayPort 1.2 Spec, Section 2.11.9.8, Table 2-98 Fixes: ad7f8a1f9ced ("drm/helper: add Displayport multi-stream helper (v0.6)") Cc: Lyude Paul <lyude@redhat.com> Cc: Todd Previte <tprevite@gmail.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Maxime Ripard <maxime.ripard@bootlin.com> Cc: Sean Paul <sean@poorly.run> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: dri-devel@lists.freedesktop.org Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Sean Paul <seanpaul@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20190829165223.129662-1-sean@poorly.run
* drm/dp_mst: Enable registration of AUX devices for MST portsVille Syrjälä2019-07-251-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All available downstream ports - physical and logical - are exposed for each MST device. They are listed in /dev/, following the same naming scheme as SST devices by appending an incremental ID. Although all downstream ports are exposed, only some will work as expected. Consider the following topology: +---------+ | ASIC | +---------+ Conn-0| | +----v----+ +----| MST HUB |----+ | +---------+ | | | |Port-1 Port-2| +-----v-----+ +-----v-----+ | MST | | SST | | Display | | Display | +-----------+ +-----------+ |Port-1 x MST Path | MST Device ----------+---------------------------------- sst:0 | MST Hub mst:0-1 | MST Display mst:0-1-1 | MST Display's disconnected DP out mst:0-1-8 | MST Display's internal sink mst:0-2 | SST Display On certain MST displays, the upstream physical port will ACK DPCD reads. However, reads on the local logical port to the internal sink will *NAK*. i.e. reading mst:0-1 ACKs, but mst:0-1-8 NAKs. There may also be duplicates. Some displays will return the same GUID when reading DPCD from both mst:0-1 and mst:0-1-8. There are some device-dependent behavior as well. The MST hub used during testing will actually *ACK* read requests on a disconnected physical port, whereas the MST displays will NAK. In light of these discrepancies, it's simpler to expose all downstream ports - both physical and logical - and let the user decide what to use. v3 changes: * Change WARN_ON_ONCE -> DRM_ERROR on dpcd read errors * Docstring and cosmetic fixes v2 changes: Moved remote aux device (un)registration to new mst connector late register and early unregister helpers. Drivers should call these from their own mst connector function hooks. This is to solve an issue during driver unload, where mst connector devices are unregistered before the remote aux devices are. In a setup where aux devices are created as children of connector devices, the aux device would be removed too early, and uncleanly. Doing so in early_unregister solves this issue, as that is called before connector unregistration. Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Leo Li <sunpeng.li@amd.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Harry Wentland <harry.wentland@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190723232808.28128-3-sunpeng.li@amd.com
* Merge v5.0-rc7 into drm-nextDave Airlie2019-02-181-1/+2
|\ | | | | | | | | | | Backmerging for nouveau and imx that needed some fixes for next pulls. Signed-off-by: Dave Airlie <airlied@redhat.com>
| * drm/dp_mst: Add __must_check to drm_dp_mst_topology_mgr_resume()Lyude Paul2019-01-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since I've had to fix two cases of drivers not checking the return code from this function, let's make the compiler complain so this doesn't come up again in the future. Changes since v1: * Remove unneeded __must_check in function declaration - danvet Signed-off-by: Lyude Paul <lyude@redhat.com> Cc: Jerry Zuo <Jerry.Zuo@amd.com> Reviewed-by: Daniel Vetter <daniel@ffwll.ch> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190108211133.32564-4-lyude@redhat.com
* | drm/dp_mst: Start tracking per-port VCPI allocationsLyude Paul2019-01-101-7/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There has been a TODO waiting for quite a long time in drm_dp_mst_topology.c: /* We cannot rely on port->vcpi.num_slots to update * topology_state->avail_slots as the port may not exist if the parent * branch device was unplugged. This should be fixed by tracking * per-port slot allocation in drm_dp_mst_topology_state instead of * depending on the caller to tell us how many slots to release. */ That's not the only reason we should fix this: forcing the driver to track the VCPI allocations throughout a state's atomic check is error prone, because it means that extra care has to be taken with the order that drm_dp_atomic_find_vcpi_slots() and drm_dp_atomic_release_vcpi_slots() are called in in order to ensure idempotency. Currently the only driver actually using these helpers, i915, doesn't even do this correctly: multiple ->best_encoder() checks with i915's current implementation would not be idempotent and would over-allocate VCPI slots, something I learned trying to implement fallback retraining in MST. So: simplify this whole mess, and teach drm_dp_atomic_find_vcpi_slots() and drm_dp_atomic_release_vcpi_slots() to track the VCPI allocations for each port. This allows us to ensure idempotency without having to rely on the driver as much. Additionally: the driver doesn't need to do any kind of VCPI slot tracking anymore if it doesn't need it for it's own internal state. Additionally; this adds a new drm_dp_mst_atomic_check() helper which must be used by atomic drivers to perform validity checks for the new VCPI allocations incurred by a state. Also: update the documentation and make it more obvious that these /must/ be called by /all/ atomic drivers supporting MST. Changes since v9: * Add some missing changes that were requested by danvet that I forgot about after I redid all of the kref stuff: * Remove unnecessary state changes in intel_dp_mst_atomic_check * Cleanup atomic check logic for VCPI allocations - all we need to check in compute_config is whether or not this state disables a CRTC, then free VCPI based off that Changes since v8: * Fix compile errors, whoops! Changes since v7: - Don't check for mixed stale/valid VCPI allocations, just rely on connector registration to stop such erroneous modesets Changes since v6: - Keep a kref to all of the ports we have allocations on. This required a good bit of changing to when we call drm_dp_find_vcpi_slots(), mainly that we need to ensure that we only redo VCPI allocations on actual mode or CRTC changes, not crtc_state->active changes. Additionally, we no longer take the registration of the DRM connector for each port into account because so long as we have a kref to the port in the new or previous atomic state, the connector will stay registered. - Use the small changes to drm_dp_put_port() to add even more error checking to make misusage of the helpers more obvious. I added this after having to chase down various use-after-free conditions that started popping up from the new helpers so no one else has to troubleshoot that. - Move some accidental DRM_DEBUG_KMS() calls to DRM_DEBUG_ATOMIC() - Update documentation again, note that find/release() should both not be called on the same port in a single atomic check phase (but multiple calls to one or the other is OK) Changes since v4: - Don't skip the atomic checks for VCPI allocations if no new VCPI allocations happen in a state. This makes the next change I'm about to list here a lot easier to implement. - Don't ignore VCPI allocations on destroyed ports, instead ensure that when ports are destroyed and still have VCPI allocations in the topology state, the only state changes allowed are releasing said ports' VCPI. This prevents a state with a mix of VCPI allocations from destroyed ports, and allocations from valid ports. Changes since v3: - Don't release VCPI allocations in the topology state immediately in drm_dp_atomic_release_vcpi_slots(), instead mark them as 0 and skip over them in drm_dp_mst_duplicate_state(). This makes it so drm_dp_atomic_release_vcpi_slots() is still idempotent while also throwing warnings if the driver messes up it's book keeping and tries to release VCPI slots on a port that doesn't have any pre-existing VCPI allocation - danvet - Change mst_state/state in some debugging messages to "mst state" Changes since v2: - Use kmemdup() for duplicating MST state - danvet - Move port validation out of duplicate state callback - danvet - Handle looping through MST topology states in drm_dp_mst_atomic_check() so the driver doesn't have to do it - Fix documentation in drm_dp_atomic_find_vcpi_slots() - Move the atomic check for each individual topology state into it's own function, reduces indenting - Don't consider "stale" MST ports when calculating the bandwidth requirements. This is needed because originally we relied on the state duplication functions to prune any stale ports from the new state, which would prevent us from incorrectly considering their bandwidth requirements alongside legitimate new payloads. - Add function references in drm_dp_atomic_release_vcpi_slots() - danvet - Annotate atomic VCPI and atomic check functions with __must_check - danvet Changes since v1: - Don't use the now-removed ->atomic_check() for private objects hook, just give drivers a function to call themselves Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@redhat.com> Cc: Jerry Zuo <Jerry.Zuo@amd.com> Cc: Harry Wentland <harry.wentland@amd.com> Cc: Juston Li <juston.li@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190111005343.17443-19-lyude@redhat.com
* | drm/dp_mst: Add some atomic state iterator macrosLyude Paul2019-01-101-0/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Changes since v6: - Move EXPORT_SYMBOL() for drm_dp_mst_topology_state_funcs to this commit - Document __drm_dp_mst_state_iter_get() and note that it shouldn't be called directly Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@redhat.com> Cc: Jerry Zuo <Jerry.Zuo@amd.com> Cc: Harry Wentland <harry.wentland@amd.com> Cc: Juston Li <juston.li@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190111005343.17443-18-lyude@redhat.com
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