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* ALSA: usb-audio: Fix recursive locking at XRUN during syncingTakashi Iwai2023-03-211-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | The recent support of low latency playback in USB-audio driver made the snd_usb_queue_pending_output_urbs() function to be called via PCM ack ops. In the new code path, the function is performed already in the PCM stream lock. The problem is that, when an XRUN is detected, the function calls snd_pcm_xrun() to notify, but snd_pcm_xrun() is supposed to be called only outside the stream lock. As a result, it leads to a deadlock of PCM stream locking. For avoiding such a recursive locking, this patch adds an additional check to the code paths in PCM core that call the ack callback; now it checks the error code from the callback, and if it's -EPIPE, the XRUN is handled in the PCM core side gracefully. Along with it, the USB-audio driver code is changed to follow that, i.e. -EPIPE is returned instead of the explicit snd_pcm_xrun() call when the function is performed already in the stream lock. Fixes: d5f871f89e21 ("ALSA: usb-audio: Improved lowlatency playback support") Reported-and-tested-by: John Keeping <john@metanate.com> Link: https://lore.kernel.org/r/20230317195128.3911155-1-john@metanate.com Reviewed-by: Jaroslav Kysela <perex@perex.cz> Reviewed-by; Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20230320142838.494-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Add new quirk FIXED_RATE for JBL Quantum810 WirelessJaroslav Kysela2022-12-221-1/+2
| | | | | | | | | | | | | | It seems that the firmware is broken and does not accept the UAC_EP_CS_ATTR_SAMPLE_RATE URB. There is only one rate (48000Hz) available in the descriptors for the output endpoint. Create a new quirk QUIRK_FLAG_FIXED_RATE to skip the rate setup when only one rate is available (fixed). BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216798 Signed-off-by: Jaroslav Kysela <perex@perex.cz> Link: https://lore.kernel.org/r/20221215153037.1163786-1-perex@perex.cz Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Split endpoint setups for hw_params and prepare (take#2)Takashi Iwai2022-09-201-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a second attempt to fix the bug appearing on Android with the recent kernel; the first try was ff878b408a03 and reverted at commit 79764ec772bc. The details taken from the v1 patch: One of the former changes for the endpoint management was the more consistent setup of endpoints at hw_params. snd_usb_endpoint_configure() is a single function that does the full setup, and it's called from both PCM hw_params and prepare callbacks. Although the EP setup at the prepare phase is usually skipped (by checking need_setup flag), it may be still effective in some cases like suspend/resume that requires the interface setup again. As it's a full and single setup, the invocation of snd_usb_endpoint_configure() includes not only the USB interface setup but also the buffer release and allocation. OTOH, doing the buffer release and re-allocation at PCM prepare phase is rather superfluous, and better to be done only in the hw_params phase. For those optimizations, this patch splits the endpoint setup to two phases: snd_usb_endpoint_set_params() and snd_usb_endpoint_prepare(), to be called from hw_params and from prepare, respectively. Note that this patch changes the driver operation slightly, effectively moving the USB interface setup again to PCM prepare stage instead of hw_params stage, while the buffer allocation and such initializations are still done at hw_params stage. And, the change of the USB interface setup timing (moving to prepare) gave an interesting "fix", too: it was reported that the recent kernels caused silent output at the beginning on playbacks on some devices on Android, and this change casually fixed the regression. It seems that those devices are picky about the sample rate change (or the interface change?), and don't follow the too immediate rate changes. Meanwhile, Android operates the PCM in the following order: - open, then hw_params with the possibly highest sample rate - close without prepare - re-open, hw_params with the normal sample rate - prepare, and start streaming This procedure ended up the hw_params twice with different rates, and because the recent kernel did set up the sample rate twice one and after, it screwed up the device. OTOH, the earlier kernels didn't set up the USB interface at hw_params, hence this problem didn't appear. Now, with this patch, the USB interface setup is again back to the prepare phase, and it works around the problem automagically. Although we should address the sample rate problem in a more solid way in future, let's keep things working as before for now. *** What's new in the take#2 patch: - The regression caused by the v1 patch (bko#216500) was due to the missing check of need_setup flag at hw_params. Now the check is added, and the snd_usb_endpoint_set_params() call is skipped when the running EP is re-opened. - There was another bug in v1 where the clock reference rate wasn't updated at hw_params phase, which may lead to a lack of the proper hw constraints when an application doesn't issue the prepare but only the hw_params call. This patch fixes it as well by tracking the clock rate change in the prepare callback with a new flag "need_update" for the clock reference object, just like others. - The configure_endpoints() are simplified and folded back into snd_usb_pcm_prepare(). Fixes: bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management") Fixes: ff878b408a03 ("ALSA: usb-audio: Split endpoint setups for hw_params and prepare") Reported-by: chihhao chen <chihhao.chen@mediatek.com> Link: https://lore.kernel.org/r/87e6d6ae69d68dc588ac9acc8c0f24d6188375c3.camel@mediatek.com Link: https://lore.kernel.org/r/20220901124136.4984-1-tiwai@suse.de Link: https://bugzilla.kernel.org/show_bug.cgi?id=216500 Link: https://lore.kernel.org/r/20220920181106.4894-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* Revert "ALSA: usb-audio: Split endpoint setups for hw_params and prepare"Takashi Iwai2022-09-201-4/+2
| | | | | | | | | | | | | | | | This reverts commit ff878b408a03bef5d610b7e2302702e16a53636e. Unfortunately the recent fix seems bringing another regressions with PulseAudio / pipewire, at least for Steinberg and MOTU devices. As a temporary solution, do a straight revert. The issue for Android will be revisited again later by another different fix (if any). Fixes: ff878b408a03 ("ALSA: usb-audio: Split endpoint setups for hw_params and prepare") Cc: <stable@vger.kernel.org> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216500 Link: https://lore.kernel.org/r/20220920113929.25162-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Split endpoint setups for hw_params and prepareTakashi Iwai2022-09-011-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the former changes for the endpoint management was the more consistent setup of endpoints at hw_params. snd_usb_endpoint_configure() is a single function that does the full setup, and it's called from both PCM hw_params and prepare callbacks. Although the EP setup at the prepare phase is usually skipped (by checking need_setup flag), it may be still effective in some cases like suspend/resume that requires the interface setup again. As it's a full and single setup, the invocation of snd_usb_endpoint_configure() includes not only the USB interface setup but also the buffer release and allocation. OTOH, doing the buffer release and re-allocation at PCM prepare phase is rather superfluous, and better to be done only in the hw_params phase. For those optimizations, this patch splits the endpoint setup to two phases: snd_usb_endpoint_set_params() and snd_usb_endpoint_prepare(), to be called from hw_params and from prepare, respectively. Note that this patch changes the driver operation slightly, effectively moving the USB interface setup again to PCM prepare stage instead of hw_params stage, while the buffer allocation and such initializations are still done at hw_params stage. And, the change of the USB interface setup timing (moving to prepare) gave an interesting "fix", too: it was reported that the recent kernels caused silent output at the beginning on playbacks on some devices on Android, and this change casually fixed the regression. It seems that those devices are picky about the sample rate change (or the interface change?), and don't follow the too immediate rate changes. Meanwhile, Android operates the PCM in the following order: - open, then hw_params with the possibly highest sample rate - close without prepare - re-open, hw_params with the normal sample rate - prepare, and start streaming This procedure ended up the hw_params twice with different rates, and because the recent kernel did set up the sample rate twice one and after, it screwed up the device. OTOH, the earlier kernels didn't set up the USB interface at hw_params, hence this problem didn't appear. Now, with this patch, the USB interface setup is again back to the prepare phase, and it works around the problem automagically. Although we should address the sample rate problem in a more solid way in future, let's keep things working as before for now. Fixes: bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management") Cc: <stable@vger.kernel.org> Reported-by: chihhao chen <chihhao.chen@mediatek.com> Link: https://lore.kernel.org/r/87e6d6ae69d68dc588ac9acc8c0f24d6188375c3.camel@mediatek.com Link: https://lore.kernel.org/r/20220901124136.4984-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Avoid killing in-flight URBs during drainingTakashi Iwai2021-09-301-1/+1
| | | | | | | | | | | | | | | | | | | While draining a stream, ALSA PCM core stops the stream by issuing snd_pcm_stop() after all data has been sent out. And, at PCM trigger stop, currently USB-audio driver kills the in-flight URBs explicitly, then at sync-stop ops, sync with the finish of all remaining URBs. This might result in a drop of the drained samples as most of USB-audio devices / hosts allow relatively long in-flight samples (as a sort of FIFO). For avoiding the trimming, this patch changes the stream-stop behavior during PCM draining state. Under that condition, the pending URBs won't be killed. The leftover in-flight URBs are caught by the sync-stop operation that shall be performed after the trigger-stop operation. Link: https://lore.kernel.org/r/20210929080844.11583-10-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Improved lowlatency playback supportTakashi Iwai2021-09-301-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is another attempt to improve further the handling of playback stream in the low latency mode. The latest workaround in commit 4267c5a8f313 ("ALSA: usb-audio: Work around for XRUN with low latency playback") revealed that submitting URBs forcibly in advance may trigger XRUN easily. In the classical mode, this problem was avoided by practically delaying the submission of the actual data with the pre-submissions of silent data before triggering the stream start. But that is exactly what we want to avoid. Now, in this patch, instead of the previous workaround, we take a similar approach as used in the implicit feedback mode. The URBs are queued at the PCM trigger start like before, but we check whether the buffer has been already filled enough before each submission, and stop queuing if the data overcomes the threshold. The remaining URBs are kept in the ready list, and they will be retrieved in the URB complete callback of other (already queued) URBs. In the complete callback, we try to fill the data and submit as much as possible again. When there is no more available in-flight URBs that may handle the pending data, we'll check in PCM ack callback and submit and process URBs there in addition. In this way, the amount of in-flight URBs may vary dynamically and flexibly depending on the available data without hitting XRUN. The following things are changed to achieve the behavior above: * The endpoint prepare callback is changed to return an error code; when there is no enough data available, it may return -EAGAIN. Currently only prepare_playback_urb() returns the error. The evaluation of the available data is a bit messy here; we can't check with snd_pcm_avail() at the point of prepare callback (as runtime->status->hwptr hasn't been updated yet), hence we manually estimate the appl_ptr and compare with the internal hwptr_done to calculate the available frames. * snd_usb_endpoint_start() doesn't submit full URBs if the prepare callback returns -EAGAIN, and puts the remaining URBs to the ready list for the later submission. * snd_complete_urb() treats the URBs in the low-latency mode similarly like the implicit feedback mode, and submissions are done in (now exported) snd_usb_queue_pending_output_urbs(). * snd_usb_queue_pending_output_urbs() again checks the error value from the prepare callback. If it's -EAGAIN for the normal stream (i.e. not implicit feedback mode), we push it back to the ready list again. * PCM ack callback is introduced for the playback stream, and it calls snd_usb_queue_pending_output_urbs() if there is no in-flight URB while the stream is running. This corresponds to the case where the system needs the appl_ptr update for re-submitting a new URB. * snd_usb_queue_pending_output_urbs() and the prepare EP callback receive in_stream_lock argument, which is a bool flag indicating the call path from PCM ack. It's needed for avoiding the deadlock of snd_pcm_period_elapsed() calls. * Set the new SNDRV_PCM_INFO_EXPLICIT_SYNC flag when the new low-latency mode is deployed. This assures catching each applptr update even in the mmap mode. Fixes: 4267c5a8f313 ("ALSA: usb-audio: Work around for XRUN with low latency playback") Link: https://lore.kernel.org/r/20210929080844.11583-9-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Check available frames for the next packet sizeTakashi Iwai2021-09-301-1/+2
| | | | | | | | | | | | | | | This is yet more preparation for the upcoming changes. Extend snd_usb_endpoint_next_packet_size() to check the available frames and return -EAGAIN if the next packet size is equal or exceeds the given size. This will be needed for avoiding XRUN during the low latency operation. As of this patch, avail=0 is passed, i.e. the check is skipped and no behavior change. Link: https://lore.kernel.org/r/20210929080844.11583-7-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Restrict rates for the shared clocksTakashi Iwai2021-09-301-0/+1
| | | | | | | | | | | | | When a single clock source is shared among several endpoints, we have to keep the same rate on all active endpoints as long as the clock is being used. For dealing with such a case, this patch adds one more check in the hw params constraint for the rate to take the shared clocks into account. The current rate is evaluated from the endpoint list that applies the same clock source. BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1190418 Link: https://lore.kernel.org/r/20210929080844.11583-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Remove the repeated declarationShaokun Zhang2021-05-301-1/+0
| | | | | | | | | Function 'snd_usb_endpoint_suspend' is declared twice, so remove the repeated declaration. Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com> Link: https://lore.kernel.org/r/1622278926-63857-1-git-send-email-zhangshaokun@hisilicon.com Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Avoid unnecessary interface re-setupTakashi Iwai2021-01-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | The current endpoint handling assumed (more or less) a unique 1:1 relation between the endpoint and the iface/altset. The exception was the sync EP without the implicit feedback which has usually the secondary EP of the same altset. This works fine for most devices, but it turned out that some unusual devices like Pinoeer's ones have both playback and capture endpoints in the same iface/altsetting and use both for the implicit feedback mode. For handling such a case, we need to extend the endpoint management to take the shared interface into account. This patch does that: it adds a new object snd_usb_iface_ref for managing the reference counts of the each USB interface that is used by each endpoint. The interface setup is performed only once for the (sharing) endpoints, and the doubly initialization is avoided. Along with this, the resource release of endpoints and interface refcounts are put into a single function, snd_usb_endpoint_free_all() instead of looping in the caller side. Fixes: bf6313a0ff76 ("ALSA: usb-audio: Refactor endpoint management") Link: https://lore.kernel.org/r/20210108075219.21463-4-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Unify the code for the next packet size calculationTakashi Iwai2020-11-231-2/+2
| | | | | | | | | | | There are two places calculating the next packet size for the playback stream in the exactly same way. Provide the single helper for this purpose and use it from both places gracefully. Tested-by: Keith Milner <kamilner@superlative.org> Tested-by: Dylan Robinson <dylan_robinson@motu.com> Link: https://lore.kernel.org/r/20201123085347.19667-32-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Constify audioformat pointer referencesTakashi Iwai2020-11-231-1/+1
| | | | | | | | | | The audioformat is referred in many places but most of usages are read-only. Let's add const prefix in the possible places. Tested-by: Keith Milner <kamilner@superlative.org> Tested-by: Dylan Robinson <dylan_robinson@motu.com> Link: https://lore.kernel.org/r/20201123085347.19667-28-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Refactor endpoint managementTakashi Iwai2020-11-231-19/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an intensive surgery for the endpoint and stream management for achieving more robust and clean code. The goals of this patch are: - More clear endpoint resource changes - The interface altsetting control in a single place Below are brief description of the whole changes. First off, most of the endpoint operations are moved into endpoint.c, so that the snd_usb_endpoint object is only referred in other places. The endpoint object is acquired and released via the new functions snd_usb_endpoint_open() and snd_usb_endpoint_close() that are called at PCM hw_params and hw_free callbacks, respectively. Those are ref-counted and EPs can manage the multiple opens. The open callback receives the audioformat and hw_params arguments, and those are used for initializing the EP parameters; especially the endpoint, interface and altset numbers are read from there, as well as the PCM parameters like the format, rate and channels. Those are stored in snd_usb_endpoint object. If it's the secondary open, the function checks whether the given parameters are compatible with the already opened EP setup, too. The coupling with a sync EP (including an implicit feedback sync) is done by the sole snd_usb_endpoint_set_sync() call. The configuration of each endpoint is done in a single shot via snd_usb_endpoint_configure() call. This is the place where most of PCM configurations are done. A few flags and special handling in the snd_usb_substream are dropped along with this change. A significant difference wrt the configuration from the previous code is the order of USB host interface setups. Now the interface is always disabled at beginning and (re-)enabled at the last step of snd_usb_endpoint_configure(), in order to be compliant with the standard UAC2/3. For UAC1, the interface is set before the parameter setups since there seem devices that require it (e.g. Yamaha THR10), just like how it was done in the previous driver code. The start/stop are almost same as before, also single-shots. The URB callbacks need to be set via snd_usb_endpoint_set_callback() like the previous code at the trigger phase, too. Finally, the flag for the re-setup is set at the device suspend through the full EP list, instead of PCM trigger. This catches the overlooked cases where the PCM hasn't been running yet but the device needs the full setup after resume. Tested-by: Keith Milner <kamilner@superlative.org> Tested-by: Dylan Robinson <dylan_robinson@motu.com> Link: https://lore.kernel.org/r/20201123085347.19667-26-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Set callbacks via snd_usb_endpoint_set_callback()Takashi Iwai2020-11-231-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | The prepare_data_urb and retire_data_urb fields of the endpoint object are set dynamically at PCM trigger start/stop. Those are evaluated in the endpoint handler, but there can be a race, especially if two different PCM substreams are handling the same endpoint for the implicit feedback case. Also, the data_subs field of the endpoint is set and accessed dynamically, too, which has the same risk. As a slight improvement for the concurrency, this patch introduces the function to set the callbacks and the data in a shot with the memory barrier. In the reader side, it's also fetched with the memory barrier. There is still a room of race if prepare and retire callbacks are set during executing the URB completion. But such an inconsistency may happen only for the implicit fb source, i.e. it's only about the capture stream. And luckily, the capture stream never sets the prepare callback, hence the problem doesn't happen practically. Tested-by: Keith Milner <kamilner@superlative.org> Tested-by: Dylan Robinson <dylan_robinson@motu.com> Link: https://lore.kernel.org/r/20201123085347.19667-23-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Create endpoint objects at parsing phaseTakashi Iwai2020-11-231-5/+5
| | | | | | | | | | | | | | | | | | | Currently snd_usb_endpoint objects are created at first when the substream is opened and tries to assign the endpoints corresponding to the matching audioformat. But since basically the all endpoints have been already parsed and the information have been obtained, we may create the endpoint objects statically at the init phase. It's easier to manage for the implicit fb case, for example. This patch changes the endpoint object management and lets the parser to create the all endpoint objects. This change shouldn't bring any functional changes. Tested-by: Keith Milner <kamilner@superlative.org> Tested-by: Dylan Robinson <dylan_robinson@motu.com> Link: https://lore.kernel.org/r/20201123085347.19667-15-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Add snd_usb_get_endpoint() helperTakashi Iwai2020-11-231-0/+4
| | | | | | | | | | | | | Factor out the code to obtain snd_usb_endpoint object matching with the given endpoint. It'll be used in the later patch to add the implicit feedback hw-constraint. No functional change by this patch itself. Tested-by: Keith Milner <kamilner@superlative.org> Tested-by: Dylan Robinson <dylan_robinson@motu.com> Link: https://lore.kernel.org/r/20201123085347.19667-6-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Improve frames size computationAlexander Tsoy2020-04-241-0/+1
| | | | | | | | | | | | | | | | | | | | | | | For computation of the the next frame size current value of fs/fps and accumulated fractional parts of fs/fps are used, where values are stored in Q16.16 format. This is quite natural for computing frame size for asynchronous endpoints driven by explicit feedback, since in this case fs/fps is a value provided by the feedback endpoint and it's already in the Q format. If an error is accumulated over time, the device can adjust fs/fps value to prevent buffer overruns/underruns. But for synchronous endpoints the accuracy provided by these computations is not enough. Due to accumulated error the driver periodically produces frames with incorrect size (+/- 1 audio sample). This patch fixes this issue by implementing a different algorithm for frame size computation. It is based on accumulating of the remainders from division fs/fps and it doesn't accumulate errors over time. This new method is enabled for synchronous and adaptive playback endpoints. Signed-off-by: Alexander Tsoy <alexander@tsoy.me> Link: https://lore.kernel.org/r/20200424022449.14972-1-alexander@tsoy.me Signed-off-by: Takashi Iwai <tiwai@suse.de>
* License cleanup: add SPDX GPL-2.0 license identifier to files with no licenseGreg Kroah-Hartman2017-11-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: usb-audio: Fix irq/process data synchronizationIoan-Adrian Ratiu2017-01-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 16200948d83 ("ALSA: usb-audio: Fix race at stopping the stream") was incomplete causing another more severe kernel panic, so it got reverted. This fixes both the original problem and its fallout kernel race/crash. The original fix is to move the endpoint member NULL clearing logic inside wait_clear_urbs() so the irq triggering the urb completion doesn't call retire_capture/playback_urb() after the NULL clearing and generate a panic. However this creates a new race between snd_usb_endpoint_start()'s call to wait_clear_urbs() and the irq urb completion handler which again calls retire_capture/playback_urb() leading to a new NULL dereference. We keep the EP deactivation code in snd_usb_endpoint_start() because removing it will break the EP reference counting (see [1] [2] for info), however we don't need the "can_sleep" mechanism anymore because a new function was introduced (snd_usb_endpoint_sync_pending_stop()) which synchronizes pending stops and gets called inside the pcm prepare callback. It also makes sense to remove can_sleep because it was also removed from deactivate_urbs() signature in [3] so we benefit from more simplification. [1] commit 015618b90 ("ALSA: snd-usb: Fix URB cancellation at stream start") [2] commit e9ba389c5 ("ALSA: usb-audio: Fix scheduling-while-atomic bug in PCM capture stream") [3] commit ccc1696d5 ("ALSA: usb-audio: simplify endpoint deactivation code") Fixes: f8114f8583bb ("Revert "ALSA: usb-audio: Fix race at stopping the stream"") Signed-off-by: Ioan-Adrian Ratiu <adi@adirat.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Pass direct struct pointer instead of list_headTakashi Iwai2014-11-041-1/+1
| | | | | | | | | | | | Some functions in mixer.c and endpoint.c receive list_head instead of the object itself. This is not obvious and rather error-prone. Let's pass the proper object directly instead. The functions in midi.c still receive list_head and this can't be changed since the object definition isn't exposed to the outside of midi.c, so left as is. Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Fix races at disconnection and PCM closingTakashi Iwai2014-06-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | When a USB-audio device is disconnected while PCM is still running, we still see some race: the disconnect callback calls snd_usb_endpoint_free() that calls release_urbs() and then kfree() while a PCM stream would be closed at the same time and calls stop_endpoints() that leads to wait_clear_urbs(). That is, the EP object might be deallocated while a PCM stream is syncing with wait_clear_urbs() with the same EP. Basically calling multiple wait_clear_urbs() would work fine, also calling wait_clear_urbs() and release_urbs() would work, too, as wait_clear_urbs() just reads some fields in ep. The problem is the succeeding kfree() in snd_pcm_endpoint_free(). This patch moves out the EP deallocation into the later point, the destructor callback. At this stage, all PCMs must have been already closed, so it's safe to free the objects. Reported-by: Alan Stern <stern@rowland.harvard.edu> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: void return type of snd_usb_endpoint_deactivate()Eldad Zack2013-10-071-1/+1
| | | | | | | | | | The return value of snd_usb_endpoint_deactivate() is not used, make the function have no return value. Update the documentation to reflect what the function is actually doing. Signed-off-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: improve buffer size computations for USB PCM audioAlan Stern2013-09-261-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the way URBs are allocated and their sizes are determined for PCM playback in the snd-usb-audio driver. Currently the driver allocates too few URBs for endpoints that don't use implicit sync, making underruns more likely to occur. This may be a holdover from before I/O delays could be measured accurately; in any case, it is no longer necessary. The patch allocates as many URBs as possible, subject to four limitations: The total number of URBs for the endpoint is not allowed to exceed MAX_URBS (which the patch increases from 8 to 12). The total number of packets per URB is not allowed to exceed MAX_PACKS (or MAX_PACKS_HS for high-speed devices), which is decreased from 20 to 6. The total duration of queued data is not allowed to exceed MAX_QUEUE, which is decreased from 24 ms to 18 ms. The total number of ALSA frames in the output queue is not allowed to exceed the ALSA buffer size. The last requirement is the hardest to implement. Currently the number of URBs needed to fill a buffer cannot be determined in advance, because a buffer contains a fixed number of frames whereas the number of frames in an URB varies to match shifts in the device's clock rate. To solve this problem, the patch changes the logic for deciding how many packets an URB should contain. Rather than using as many as possible without exceeding an ALSA period boundary, now the driver uses only as many packets as needed to transfer a predetermined number of frames. As a result, unless the device's clock has an exceedingly variable rate, the number of URBs making up each period (and hence each buffer) will remain constant. The overall effect of the patch is that playback works better in low-latency settings. The user can still specify values for frames/period and periods/buffer that exceed the capabilities of the hardware, of course. But for values that are within those capabilities, the performance will be improved. For example, testing shows that a high-speed device can handle 32 frames/period and 3 periods/buffer at 48 KHz, whereas the current driver starts to get glitchy at 64 frames/period and 2 periods/buffer. A side effect of these changes is that the "nrpacks" module parameter is no longer used. The patch removes it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Clemens Ladisch <clemens@ladisch.de> Tested-by: Daniel Mack <zonque@gmail.com> Tested-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: spelling correctionEldad Zack2013-04-041-1/+1
| | | | | | | | Correct spelling of snd_usb_endpoint_implict_feedback_sink in all occurances. Signed-off-by: Eldad Zack <eldad@fogrefinery.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: stop both data and sync endpoints asynchronouslyTakashi Iwai2012-11-211-1/+1
| | | | | | | | | | | | | | As we are stopping the endpoints asynchronously now, it's better to trigger the stop of both data and sync endpoints and wait for pending stopping operations, instead of the sequential trigger-and-wait procedure. So the wait argument in snd_usb_endpoint_stop() is dropped, and it's expected that the caller synchronizes explicitly by calling snd_usb_endpoint_sync_pending_stop(). (Actually there is only one place calling this, so it was safe to change.) Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: simplify snd_usb_endpoint_start/stop argumentsTakashi Iwai2012-11-211-3/+2
| | | | | | | | | Reduce the redundant arguments for snd_usb_endpoint_start() and snd_usb_endpoint_stop(). Also replaced from int to bool. No functional changes by this commit. Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Fix crash at re-preparing the PCM streamTakashi Iwai2012-11-081-0/+1
| | | | | | | | | | | | | | | | | There are bug reports of a crash with USB-audio devices when PCM prepare is performed immediately after the stream is stopped via trigger callback. It turned out that the problem is that we don't wait until all URBs are killed. This patch adds a new function to synchronize the pending stop operation on an endpoint, and calls in the prepare callback for avoiding the crash above. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=49181 Reported-and-tested-by: Artem S. Tashkinov <t.artem@lycos.com> Cc: <stable@vger.kernel.org> [v3.6] Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: Don't require hw_params in endpoint.Dylan Reid2012-09-191-1/+4
| | | | | | | | | Change the interface to configure an endpoint so that it doesn't require a hw_params struct. This will allow it to be called from prepare instead of hw_params, configuring it after system resume. Signed-off-by: Dylan Reid <dgreid@chromium.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: snd-usb: fix calls to next_packet_sizeDaniel Mack2012-08-311-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | In order to support devices with implicit feedback streaming models, packet sizes are now stored with each individual urb, and the PCM handling code which fills the buffers purely relies on the size fields now. However, calling snd_usb_audio_next_packet_size() for all possible packets in an URB at once, prior to letting the PCM code do its job does in fact not lead to the same behaviour than what the old code did: The PCM code will break its loop once a period boundary is reached, consequently using up less packets that it really could. As snd_usb_audio_next_packet_size() implements a feedback mechanism to the endpoints phase accumulator, the number of calls to that function matters, and when called too often, the data rate runs out of bounds. Fix this by making the next_packet function public, and call it from the PCM code as before if the packet data sizes are not defined. Signed-off-by: Daniel Mack <zonque@gmail.com> Cc: stable@kernel.org [v3.5+] Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: snd-usb: Fix URB cancellation at stream startDaniel Mack2012-08-301-1/+1
| | | | | | | | | | | | | | | | | Commit e9ba389c5 ("ALSA: usb-audio: Fix scheduling-while-atomic bug in PCM capture stream") fixed a scheduling-while-atomic bug that happened when snd_usb_endpoint_start was called from the trigger callback, which is an atmic context. However, the patch breaks the idea of the endpoints reference counting, which is the reason why the driver has been refactored lately. Revert that commit and let snd_usb_endpoint_start() take care of the URB cancellation again. As this function is called from both atomic and non-atomic context, add a flag to denote whether the function may sleep. Signed-off-by: Daniel Mack <zonque@gmail.com> Cc: stable@kernel.org [3.5+] Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: snd-usb: remove old streaming logicDaniel Mack2012-04-131-15/+0
| | | | | Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: snd-usb: switch over to new endpoint streaming logicDaniel Mack2012-04-131-3/+0
| | | | | | | | | With the previous commit that added the new streaming model, all endpoint and streaming related code is now in endpoint.c, and pcm.c only acts as a wrapper for handling the packet's payload. Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: snd-usb: implement new endpoint streaming modelDaniel Mack2012-04-131-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a new generic streaming logic for audio over USB. It defines a model (snd_usb_endpoint) that handles everything that is related to an USB endpoint and its streaming. There are functions to activate and deactivate an endpoint (which call usb_set_interface()), and to start and stop its URBs. It also has function pointers to be called when data was received or is about to be sent, and pointer to a sync slave (another snd_usb_endpoint) that is informed when data has been received. A snd_usb_endpoint knows about its state and implements a refcounting, so only the first user will actually start the URBs and only the last one to stop it will tear them down again. With this sort of abstraction, the actual streaming is decoupled from the pcm handling, which makes the "implicit feedback" mechanisms easy to implement. In order to split changes properly, this patch only adds the new implementation but leaves the old one around, so the the driver doesn't change its behaviour. The switch to actually use the new code is submitted separately. Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: snd-usb: move code from urb.c to endpoint.cDaniel Mack2011-09-141-0/+17
| | | | | | | | | No code altered at this point, simply preparing for upcoming refactorizations. Signed-off-by: Daniel Mack <zonque@gmail.com> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: snd-usb: re-order codeDaniel Mack2011-09-141-7/+0
| | | | | | | | | | | | Move code from endpoint.c into a new file called stream.c and rename functions so that their names actually reflect what they're doing. This way, endpoint.c will be available to functions that hold all the endpoint logic. Signed-off-by: Daniel Mack <zonque@gmail.com> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
* ALSA: usb-audio: refactor codeDaniel Mack2010-03-051-0/+11
Clean up the usb audio driver by factoring out a lot of functions to separate files. Code for procfs, quirks, urbs, format parsers etc all got a new home now. Moved almost all special quirk handling to quirks.c and introduced new generic functions to handle them, so the exceptions do not pollute the whole driver. Renamed usbaudio.c to card.c because this is what it actually does now. Renamed usbmidi.c to midi.c for namespace clarity. Removed more things from usbaudio.h. The non-standard drivers were adopted accordingly. Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>