summaryrefslogtreecommitdiffstats
path: root/drivers/usb/host/ehci-hcd.c
Commit message (Collapse)AuthorAgeFilesLines
...
* USB: EHCI: DT support for generic bus glueArnd Bergmann2013-03-281-5/+0
| | | | | | | | | | | | | This lets us use the ehci-platform driver on platforms without special requirements for their ehci controllers. In particular, this is true for the vt8500/wm8x50 platforms, which currently have a separate driver that causes problems with multiplatform configurations. Tested-by: Tony Prisk <linux@prisktech.co.nz> Tested-by: Peter Vasil <petervasil@gmail.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: improve end_unlink_async()Alan Stern2013-03-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1665) changes the way ehci-hcd's end_unlink_async() routine works in order to avoid recursive execution and to be more efficient: Now when an IAA cycle ends, a new one gets started up right away (if it is needed) instead of waiting until the just-unlinked QH has been processed. The async_iaa list is renamed to async_idle, which better expresses its new purpose: It is now the list of QHs which are now completely idle and are waiting to be processed by end_unlink_async(). A new flag is added to track whether an IAA cycle is in progress, because the list formerly known as async_iaa no longer stores the QHs waiting for the IAA to finish. The decision about how many QHs to process when an IAA cycle ends is now made at the end of the cycle, when we know the current state of the hardware, rather than at the beginning. This means a bunch of logic got moved from start_iaa_cycle() to end_unlink_async(). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: convert singly-linked lists to list_headsAlan Stern2013-03-251-1/+4
| | | | | | | | | | | | | | | This patch (as1664) converts ehci-hcd's async_unlink, async_iaa, and intr_unlink from singly-linked lists to standard doubly-linked list_heads. Originally it didn't seem necessary to use list_heads, because items are always added to and removed from these lists in FIFO order. But now with more list processing going on, it's easier to use the standard routines than continue with a roll-your-own approach. I don't know if the code ends up being notably shorter, but the patterns will be more familiar to any kernel hacker. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: consolidate code in ehci_urb_dequeue()Alan Stern2013-03-251-37/+11
| | | | | | | | | | | This patch (as1668) consolidates two nearly identical code paths in ehci_urb_dequeue(). The test for !qh can be removed because it will never succeed; the fact that usb_hcd_check_unlink_urb() returned 0 means that urb must be queued and therefore urb->hcpriv must point to a QH. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: split needs_rescan into two flagsAlan Stern2013-03-251-5/+11
| | | | | | | | | | | | | | | | | | | | This patch (as1662) does some more QH-related cleanup in ehci-hcd. The qh->needs_rescan flag is currently used for two different purposes; the patch replaces it with two separate flags for greater clarity: qh->dequeue_during_giveback indicates that a completion handler dequeued an URB (implying that a rescan is needed), and qh->exception indicates that the QH is in an exceptional state requiring an unlink (either it encountered an I/O error or an unlink was requested). The new flags get set where the dequeue, exception, or unlink request occurred, rather than where the unlink is started. This is so that in the future, if we need to, we will be able to tell apart unlinks that truly were required from those that were carried out merely because the QH wasn't being used. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'usb-linus' into usb-nextGreg Kroah-Hartman2013-03-201-4/+3
|\ | | | | | | | | | | | | | | This is to pick up the fixes in that branch, and let Alan fix the merge error in drivers/usb/host/ehci-timer.c better than I just did (as I know I messed it up...) Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: fix regression during bus resumeAlan Stern2013-03-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1663) fixes a regression caused by commit 6e0c3339a6f19d748f16091d0a05adeb1e1f822b (USB: EHCI: unlink one async QH at a time). In order to avoid keeping multiple QHs in an unusable intermediate state, that commit changed unlink_empty_async() so that it unlinks only one empty QH at a time. However, when the EHCI root hub is suspended, _all_ async QHs need to be unlinked. ehci_bus_suspend() used to do this by calling unlink_empty_async(), but now this only unlinks one of the QHs, not all of them. The symptom is that when the root hub is resumed, USB communications don't work for some period of time. This is because ehci-hcd doesn't realize it needs to restart the async schedule; it assumes that because some QHs are already on the schedule, the schedule must be running. The easiest way to fix the problem is add a new function that unlinks all the async QHs when the root hub is suspended. This patch should be applied to all kernels that have the 6e0c3339a6f1 commit. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-tested-by: Adrian Bassett <adrian.bassett@hotmail.co.uk> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: work around silicon bug in Intel's EHCI controllersAlan Stern2013-03-051-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1660) works around a hardware problem present in some (if not all) Intel EHCI controllers. After a QH has been unlinked from the async schedule and the corresponding IAA interrupt has occurred, the controller is not supposed access the QH and its qTDs. There certainly shouldn't be any more DMA writes to those structures. Nevertheless, Intel's controllers have been observed to perform a final writeback to the QH's overlay region and to the most recent qTD. For more information and a test program to determine whether this problem is present in a particular controller, see http://marc.info/?l=linux-usb&m=135492071812265&w=2 http://marc.info/?l=linux-usb&m=136182570800963&w=2 This patch works around the problem by always waiting for two IAA cycles when unlinking an async QH. The extra IAA delay gives the controller time to perform its final writeback. Surprisingly enough, the effects of this silicon bug have gone undetected until quite recently. More through luck than anything else, it hasn't caused any apparent problems. However, it does interact badly with the path that follows this one, so it needs to be addressed. This is the first part of a fix for the regression reported at: https://bugs.launchpad.net/bugs/1088733 Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Stephen Thirlwall <sdt@dr.com> CC: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | USB: EHCI: improve use of per-port status-change bitsAlan Stern2013-03-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | This patch (as1634) simplifies some of the code associated with the per-port change bits added in EHCI-1.1, and in particular it fixes a bug in the logic of ehci_hub_status_data(). Even if the change bit doesn't indicate anything happened on a particular port, we still have to notify the core about changes to the suspend or reset status. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | USB: EHCI: split ehci-omap out to a separate driverAlan Stern2013-03-151-5/+1
|/ | | | | | | | | | This patch (as1645) converts ehci-omap over to the new "ehci-hcd is a library" approach, so that it can coexist peacefully with other EHCI platform drivers and can make use of the private area allocated at the end of struct ehci_hcd. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: notify usbcore about port resumesAlan Stern2013-01-251-0/+1
| | | | | | | | | | | This patch (as1650) adds calls to the new usb_hcd_{start,end}_port_resume() functions to ehci-hcd. Now EHCI root hubs won't be runtime suspended while they are sending a resume signal to one of their ports. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: fix build error in ehci-mxcAlan Stern2013-01-231-5/+1
| | | | | | | | | | | | | | | | | | | | | This patch (as1643b) fixes a build error in ehci-hcd when compiling for ARM with allmodconfig: drivers/usb/host/ehci-hcd.c:1285:0: warning: "PLATFORM_DRIVER" redefined [enabled by default] drivers/usb/host/ehci-hcd.c:1255:0: note: this is the location of the previous definition drivers/usb/host/ehci-mxc.c:280:31: warning: 'ehci_mxc_driver' defined but not used [-Wunused-variable] drivers/usb/host/ehci-hcd.c:1285:0: warning: "PLATFORM_DRIVER" redefined [enabled by default] drivers/usb/host/ehci-hcd.c:1255:0: note: this is the location of the previous definition The fix is to convert ehci-mxc over to the new "ehci-hcd is a library" scheme so that it can coexist peacefully with the ehci-platform driver. As part of the conversion the ehci_mxc_priv data structure, which was allocated dynamically, is now placed where it belongs: in the private area at the end of struct ehci_hcd. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: fix incorrect configuration testAlan Stern2013-01-221-1/+1
| | | | | | | | | | This patch (as1641) fixes a minor bug in ehci-hcd left over from when the Chipidea driver was converted to the "ehci-hcd is a library" scheme. The test for whether the Chipidea platform driver is active should be IS_ENABLED(), not defined(). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: Move definition of EHCI_STATS to ehci.hRoger Quadros2013-01-221-4/+0
| | | | | | | | | | | Without this, platform drivers e.g. ehci-omap.c will see a different version of struct ehci_hcd than ehci-hcd.c and break reference to 'debug_dir' and 'priv' members when CONFIG_USB_DEBUG is enabled. Signed-off-by: Roger Quadros <rogerq@ti.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: miscellaneous cleanups for the library conversionAlan Stern2012-11-111-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | This patch (as1630) cleans up a few minor items resulting from the split-up of the ehci-hcd driver: Remove the product_desc string from the ehci_driver_overrides structure. All drivers will use the generic "EHCI Host Controller" string. (This was requested by Felipe Balbi.) Allow drivers to pass a NULL pointer to ehci_init_driver() if they don't have to override any settings. Remove a #define symbol that is no longer used from the ChipIdea host driver. Rename overrides to pci_overrides in ehci-pci.c, for consistency with ehci-platform.c. Mark the *_overrides structures as __initdata. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reviewed-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: fix build error by making ChipIdea host a normal EHCI driverAlan Stern2012-11-021-10/+1
| | | | | | | | | | | | | | | | This patch (as1627) splits the ehci-hcd core code, which has become a separate library module, out from the ChipIdea host driver. Instead of #include-ing ehci-hcd.c directly, the ChipIdea module will now use the ehci-hcd library in a normal fashion. This fixes a build error caused by commit 3e0232039967d7a1a06c013d097458b4d5892af1 (USB: EHCI: prepare to make ehci-hcd a library module); I had forgotten about the unorthodox way the ChipIdea driver uses the ehci-hcd code. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: make ehci-platform a separate driverAlan Stern2012-11-011-5/+1
| | | | | | | | This patch (as1626) splits the ehci-platform code from ehci-hcd out into its own separate driver module. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: make ehci-pci a separate driverAlan Stern2012-11-011-21/+5
| | | | | | | | | | | | This patch (as1625) splits the PCI portion of ehci-hcd out into its own separate driver module, called ehci-pci. Consistently with the current practice, the decision whether to build this module is not user-configurable. If EHCI and PCI are enabled then the module will be built, always. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: prepare to make ehci-hcd a library moduleAlan Stern2012-11-011-3/+70
| | | | | | | | | | | | | | | | | This patch (as1624) prepares ehci-hcd for being split up into a core library and separate platform driver modules. A generic ehci_hc_driver structure is created, containing all the "standard" values, and a new mechanism is added whereby a driver module can specify a set of overrides to those values. In addition the ehci_setup(), ehci_suspend(), and ehci_resume() routines need to be EXPORTed for use by the drivers. As a side effect of this change, a few routines no longer need to be marked __maybe_unused. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: remove ehci_port_power() routineAlan Stern2012-10-311-21/+0
| | | | | | | | | | | | | | | This patch (as1623) removes the ehci_port_power() routine and all the places that call it. There's no reason for ehci-hcd to change the port power settings; the hub driver takes care of all that stuff. There is one exception: When the controller is resumed from hibernation or following a loss of power, the ports that are supposed to be handed over to a companion controller must be powered on first. Otherwise the handover won't work. This process is not visible to the hub driver, so it has to be handled in ehci-hcd. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: remove unused Link Power Management codeAlan Stern2012-10-311-18/+0
| | | | | | | | | | | | | | | | | | | This patch (as1622) removes the USB-2.1 Link Power Management code from the ehci-hcd driver. This code was never integrated with usbcore, it is full of bugs, and it was not getting used by anybody. However, the debugging code for dumping the LPM-related fields in the EHCI registers is left in place. In theory it might be useful to see these values, even though we don't use them. This essentially amounts to a partial revert of commit aa4d8342988d0c1a79ff19b2ede1e81dfbb16ea5 (USB: EHCI: EHCI 1.1 addendum: preparation) and an almost full revert of commit 48f24970144479c29b8cee6d2e1dbedf6dcf9cfb (USB: EHCI: EHCI 1.1 addendum: Basic LPM feature support) plus its follow-ons. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: make ehci_read_frame_index platform independentAlan Stern2012-10-241-1/+26
| | | | | | | | | | | | | | | | In preparation for splitting the ehci-hcd driver into a core library and separate platform-specific driver modules, this patch (as1617) changes the way ehci_read_frame_index() is handled. Since the same core library will have to work with both PCI and non-PCI platforms, the quirk handler routine will be compiled unconditionally. The decision about whether to call it or simply to read the frame index register is made at run time, based on whether the frame_index_bug quirk flag is set. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: remove CNS3xxx EHCI platform driverFlorian Fainelli2012-10-221-5/+0
| | | | | | | | | The users have been converted to use the ehci platform driver instead, thus making the ehci-cns3xxx driver obsolete, so remove it. Signed-off-by: Florian Fainelli <florian@openwrt.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: remove Alchemy EHCI driverFlorian Fainelli2012-10-221-5/+0
| | | | | | | | | The platform code has been converted to use the ehci-platform driver instead thus obsoleting the ehci-au1xxx driver, which can be removed. Signed-off-by: Florian Fainelli <florian@openwrt.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: remove Netlogic XLS EHCI driverFlorian Fainelli2012-10-221-5/+0
| | | | | | | | | The platform code has been migrated to register the ehci-platform driver, thus obsoleting the ehci-xls driver, which can be removed. Signed-off-by: Florian Fainelli <florian@openwrt.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: remove Loongson 1B EHCI driver.Florian Fainelli2012-10-221-5/+0
| | | | | | | | | | The platform code registering the Loongson 1B EHCI driver has now been converted to register the ehci-platform driver instead, thus obsoleting the ehci-ls1x driver, which can be removed. Signed-off-by: Florian Fainelli <florian@openwrt.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB: EHCI: remove IXP4xx EHCI driverFlorian Fainelli2012-10-221-5/+0
| | | | | | | | | | This driver is not registered by any in-tree user. If needed it the EHCI driver can be reinstatied using the ehci-platform driver with caps_offset to 0x100. Signed-off-by: Florian Fainelli <florian@openwrt.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* EHCI: use the isochronous scheduling thresholdAlan Stern2012-10-221-1/+1
| | | | | | | | | | | | | | | | This patch (as1609) changes the way ehci-hcd uses the "Isochronous Scheduling Threshold" in its calculations. Until now the code has ignored the threshold except for certain Intel PCI-based controllers. This violates the EHCI spec. The new code takes the threshold into account always, removing the need for the fs_i_thresh quirk flag. In addition it implements the "full frame cache" setting more efficiently, moving forward only as far as the next frame boundary instead of always moving forward 8 microframes. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* USB EHCI/Xen: propagate controller reset information to hypervisorJan Beulich2012-09-181-2/+2
| | | | | | | | | | | | | | | | | | Just like for the in-tree early console debug port driver, the hypervisor - when using a debug port based console - also needs to be told about controller resets, so it can suppress using and then re-initialize the debug port accordingly. Other than the in-tree driver, the hypervisor driver actually cares about doing this only for the device where the debug is port actually in use, i.e. it needs to be told the coordinates of the device being reset (quite obviously, leveraging the addition done for that would likely benefit the in-tree driver too). Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'usb-3.6-rc1' of ↵Linus Torvalds2012-07-261-286/+226
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB patches from Greg Kroah-Hartman: "Here's the big USB patch set for the 3.6-rc1 merge window. Lots of little changes in here, primarily for gadget controllers and drivers. There's some scsi changes that I think also went in through the scsi tree, but they merge just fine. All of these patches have been in the linux-next tree for a while now. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" Fix up trivial conflicts in include/scsi/scsi_device.h (same libata conflict that Jeff had already encountered) * tag 'usb-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (207 commits) usb: Add USB_QUIRK_RESET_RESUME for all Logitech UVC webcams usb: Add quirk detection based on interface information usb: s3c-hsotg: Add header file protection macros in s3c-hsotg.h USB: ehci-s5p: Add vbus setup function to the s5p ehci glue layer USB: add USB_VENDOR_AND_INTERFACE_INFO() macro USB: notify phy when root hub port connect change USB: remove 8 bytes of padding from usb_host_interface on 64 bit builds USB: option: add ZTE MF821D USB: sierra: QMI mode MC7710 moved to qcserial USB: qcserial: adding Sierra Wireless devices USB: qcserial: support generic Qualcomm serial ports USB: qcserial: make probe more flexible USB: qcserial: centralize probe exit path USB: qcserial: consolidate usb_set_interface calls USB: ehci-s5p: Add support for device tree USB: ohci-exynos: Add support for device tree USB: ehci-omap: fix compile failure(v1) usb: host: tegra: pass correct pointer in ehci_setup() USB: ehci-fsl: Update ifdef check to work on 64-bit ppc USB: serial: keyspan: Removed unrequired parentheses. ...
| * USB: EHCI: resolve some unlikely racesAlan Stern2012-07-161-1/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1589) resolves some unlikely races involving system shutdown or controller death in ehci-hcd: Shutdown races with both root-hub resume and controller resume. Controller death races with root-hub suspend. A new bitflag is added to indicate that the controller has been shut down (whether for system shutdown or because it died). Tests are added in the suspend and resume pathways to avoid reactivating the controller after any sort of shutdown. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: fix up lockingAlan Stern2012-07-161-15/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1588) adjusts the locking in ehci-hcd's various halt, shutdown, and suspend/resume pathways. We want to hold the spinlock while writing device registers and accessing shared variables, but not while polling in a loop. In addition, there's no need to call ehci_work() at times when no URBs can be active, i.e., in ehci_stop() and ehci_bus_suspend(). Finally, ehci_adjust_port_wakeup_flags() is called only in situations where interrupts are enabled; therefore it can use spin_lock_irq rather than spin_lock_irqsave. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: simplify isochronous scanningAlan Stern2012-07-161-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1587) simplifies ehci-hcd's scan_isoc() routine by eliminating some local variables, declaring boolean-valued values as bool rather than unsigned, changing variable names to make more sense, and so on. The logic at the end of the routine is cut down significantly. The scanning doesn't have to catch up all the way to where the hardware is; it merely has to catch up to where the hardware was when the last interrupt occurred. If the hardware has made more progress since then and issued another interrupt, a rescan will catch up to it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for the I/O watchdogAlan Stern2012-07-161-46/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1586) replaces the kernel timer used by ehci-hcd as an I/O watchdog with an hrtimer event. Unlike in the current code, the watchdog event is now always enabled whenever any isochronous URBs are active. This will prevent bugs caused by the periodic schedule wrapping around with no completion interrupts; the watchdog handler is guaranteed to scan the isochronous transfers at least once during each iteration of the schedule. The extra overhead will be negligible: one timer interrupt every 100 ms. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: always scan each interrupt QHAlan Stern2012-07-161-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1585) fixes a bug in ehci-hcd's scheme for scanning interrupt QHs. Currently a single routine takes care of scanning everything on the periodic schedule. Whenever an interrupt occurs, it scans all isochronous and interrupt URBs scheduled for frames that have elapsed since the last scan. This has two disadvantages. The first is relatively minor: An interrupt QH is likely to end up getting scanned multiple times, particularly if the last scan was not fairly recent. (The current code avoids this by maintaining a periodic_stamp in each interrupt QH.) The second is more serious. The periodic schedule wraps around. If the last scan occurred during frame N, and the next scan occurs when the schedule has gone through an entire cycle and is back at frame N, the scanning code won't look at any frames other than N. Consequently it won't see any QHs that completed during frame N-1 or earlier. The patch replaces the entire frame-based approach for scanning interrupt QHs with a new routine using a list-based approach, the same as for async QHs. This has a slight disadvantage, because it means that all interrupt QHs have to be scanned every time. But it is more robust than the current approach. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: don't lose events during a scanAlan Stern2012-07-161-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1584) fixes a minor bug that has been present in ehci-hcd since the beginning. Scanning the schedules for URB completions is single-threaded. If a completion interrupt occurs while an URB is being given back, the interrupt handler realizes that a scan is in progress on another CPU and avoids starting a new one. This means that completion events can be lost. If an URB completes after it has been scanned but while a scan is still in progress, the driver won't notice and won't rescan the completed URB. The patch fixes the problem by adding a new flag to indicate that another scan is needed after the current scan is done. The flag gets set whenever a completion interrupt occurs while a scan is in progress. The rescan will see the completion, thus preventing it from getting lost. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for unlinking empty async QHsAlan Stern2012-07-161-15/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1583) changes ehci-hcd to use an hrtimer event for unlinking empty (unused) async QHs instead of using a kernel timer. The check for empty QHs is moved to a new routine, where it doesn't require going through an entire scan of both the async and periodic schedules. And it can unlink multiple QHs at once, unlike the current code. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: unlink multiple async QHs togetherAlan Stern2012-07-161-31/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1582) changes ehci-hcd's strategy for unlinking async QHs. Currently the driver never unlinks more than one QH at a time. This can be inefficient and cause unnecessary delays, since a QH cannot be reused while it is waiting to be unlinked. The new strategy unlinks all the waiting QHs at once. In practice the improvement won't be very big, because it's somewhat uncommon to have two or more QHs waiting to be unlinked at any time. But it does happen, and in any case, doing things this way makes more sense IMO. The change requires the async unlinking code to be refactored slightly. Now in addition to the routines for starting and ending an unlink, there are new routines for unlinking a single QH and starting an IAA cycle. This approach is needed because there are two separate paths for unlinking async QHs: When a transfer error occurs or an URB is cancelled, the QH must be unlinked right away; When a QH has been idle sufficiently long, it is unlinked to avoid consuming DMA bandwidth uselessly. In the first case we want the unlink to proceed as quickly as possible, whereas in the second case we can afford to batch several QHs together and unlink them all at once. Hence the division of labor. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for the IAA watchdogAlan Stern2012-07-161-52/+14
| | | | | | | | | | | | | | | | | | This patch (as1581) replaces the iaa_watchdog kernel timer used by ehci-hcd with an hrtimer event, in keeping with the general conversion to high-res timers. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: don't refcount iso_stream structuresAlan Stern2012-07-161-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1580) makes ehci_iso_stream structures behave more like QHs, in that they will remain allocated until their isochronous endpoint is disabled. This will come in useful in the future, when periodic bandwidth gets allocated as an altsetting is installed rather than on-the-fly. For now, the change to the ehci_iso_stream lifetimes means that each structure is always deallocated at exactly one spot in ehci_endpoint_disable() and never used again. As a result, it is no longer necessary to use reference counting on these things, and the patch removes it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for (s)iTD deallocationAlan Stern2012-07-161-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1579) adds an hrtimer event to handle deallocation of iTDs and siTDs in ehci-hcd. Because of the frame-oriented approach used by the EHCI periodic schedule, the hardware can continue to access the Transfer Descriptor for isochronous (or split-isochronous) transactions for up to a millisecond after the transaction completes. The iTD (or siTD) must not be reused before then. The strategy currently used involves putting completed iTDs on a list of cached entries and every so often returning them to the endpoint's free list. The new strategy reduces overhead by putting completed iTDs back on the free list immediately, although they are not reused until it is safe to do so. When the isochronous endpoint stops (its queue becomes empty), the iTDs on its free list get moved to a global list, from which they will be deallocated after a minimum of 2 ms. This delay is what the new hrtimer event is for. Overall this may not be a tremendous improvement over the current code, but to me it seems a lot more clear and logical. In addition, it removes the need for each iTD to keep a reference to the ehci_iso_stream it belongs to, since the iTD never needs to be moved back to the stream's free list from the global list. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for controller deathAlan Stern2012-07-161-10/+10
| | | | | | | | | | | | | | | | | | | | | | This patch (as1578) adds an hrtimer event to handle the death of an EHCI controller. When a controller dies, it doesn't necessarily stop running right away. The new event polls at 1-ms intervals to see when all activity has safely stopped. This replaces a busy-wait polling loop in the current code. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for interrupt QH unlinkAlan Stern2012-07-161-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1577) adds hrtimer support for unlinking interrupt QHs in ehci-hcd. The current code relies on a fixed delay of either 2 or 55 us, which is not always adequate and in any case is totally bogus. Thanks to internal caching, the EHCI hardware may continue to access an interrupt QH for more than a millisecond after it has been unlinked. In fact, the EHCI spec doesn't say how long to wait before using an unlinked interrupt QH. The patch sets the delay to 9 microframes minimum, which ought to be adequate. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for async scheduleAlan Stern2012-07-161-10/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1576) adds hrtimer support for managing ehci-hcd's async schedule. Just as with the earlier change to the periodic schedule management, two new hrtimer events take care of everything. One event polls at 1-ms intervals to see when the Asynchronous Schedule Status (ASS) flag matches the Asynchronous Schedule Enable (ASE) value; the schedule's state must not be changed until it does. The other event delays for 15 ms after the async schedule becomes empty before turning it off. The new events replace a busy-wait poll and a kernel timer usage. They also replace the rather illogical method currently used for indicating the async schedule should be turned off: attempting to unlink the dedicated QH at the head of the async list. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: remove PS3 status pollingAlan Stern2012-07-161-67/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1575) removes special code added for status polling of the EHCI controller in PS3 systems. While the controller is running, the polling is now carried out by an hrtimer handler. When the controller is suspending or stopping, we use the same polling routine as the old code -- but in neither case do we need to conclude that the controller has died if the polling goes on for too long. As a result the entire handshake_on_error_set_halt() routine is now unused, so it is removed from the driver. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: use hrtimer for the periodic scheduleAlan Stern2012-07-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1573) adds hrtimer support for managing ehci-hcd's periodic schedule. There are two issues to deal with. First, the schedule's state (on or off) must not be changed until the hardware status has caught up with the current command. This is handled by an hrtimer event that polls at 1-ms intervals to see when the Periodic Schedule Status (PSS) flag matches the Periodic Schedule Enable (PSE) value. Second, the schedule should not be turned off as soon as it becomes empty. Turning the schedule on and off takes time, so we want to wait until the schedule has been empty for a suitable period before turning it off. This is handled by an hrtimer event that gets set to expire 10 ms after the periodic schedule becomes empty. The existing code polls (for up to 1125 us and with interrupts disabled!) to check the status, and doesn't implement a delay before turning off the schedule. Furthermore, if the polling fails then the driver decides that the controller has died. This has caused problems for several people; some controllers can take 10 ms or more to turn off their periodic schedules. This patch fixes these issues. It also makes the "broken_periodic" workaround unnecessary; there is no longer any danger of turning off the periodic schedule after it has been on for less than 1 ms. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: introduce high-res timerAlan Stern2012-07-161-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1572) begins the conversion of ehci-hcd over to using high-resolution timers rather than old-fashioned low-resolution kernel timers. This reduces overhead caused by timer roundoff on systems where HZ is smaller than 1000. Also, the new timer framework introduced here is much more logical and easily extended than the ad-hoc approach ehci-hcd currently uses for timers. An hrtimer structure is added to ehci_hcd, along with a bitflag array and an array of ktime_t values, to keep track of which timing events are pending and what their expiration times are. Only the infrastructure for the timing operations is added in this patch. Later patches will add routines for handling each of the various timing events the driver needs. In some cases the new hrtimer handlers will replace the existing handlers for ehci-hcd's kernel timers; as this happens the old timers will be removed. In other cases the new timing events will replace busy-wait loops. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: add new root-hub state: STOPPINGAlan Stern2012-07-161-7/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1571) adds a new state for ehci-hcd's root hubs: EHCI_RH_STOPPING. This value is used at times when the root hub is being stopped and we don't know whether or not the hardware has finished all its DMA yet. Although the purpose may not be apparent, this distinction will come in useful later on. Future patches will avoid actions that depend on the root hub being operational (like turning on the async or periodic schedules) when they see the state is EHCI_RH_STOPPING. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: add pointer to end of async-unlink listAlan Stern2012-07-161-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1570) adds a pointer for the end of ehci-hcd's async-unlink list. The list (which is actually a queue) is singly linked, so having a pointer to its end makes adding new entries easier -- there's no longer any need to scan through the whole list. In principle it could be changed to a standard doubly-linked list. It turns out that doing so actually makes the code less clear, so I'm leaving it as is. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * USB: EHCI: rename "reclaim"Alan Stern2012-07-161-13/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch (as1569) renames the ehci->reclaim list in ehci-hcd. The word "reclaim" is used in the EHCI specification to mean something quite different, and "unlink_next" is more descriptive of the list's purpose anyway. Similarly, the "reclaim" field in the ehci_stats structure is renamed "iaa", which is more meaningful (to experts, anyway) and is a better match for the "lost_iaa" field. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>