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path: root/drivers/usb/host/ehci.h
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2014-01-13usb: ehci: add freescale imx28 special write register methodPeter Chen
According to Freescale imx28 Errata, "ENGR119653 USB: ARM to USB register error issue", All USB register write operations must use the ARM SWP instruction. So, we implement a special ehci_write for imx28. Discussion for it at below: http://marc.info/?l=linux-usb&m=137996395529294&w=2 Without this patcheset, imx28 works unstable at high AHB bus loading. If the bus loading is not high, the imx28 usb can work well at the most of time. There is a IC errata for this problem, usually, we consider IC errata is a problem not a new feature, and this workaround is needed for that, so we need to add them to stable tree 3.11+. Cc: stable@vger.kernel.org Cc: robert.hodaszi@digi.com Signed-off-by: Peter Chen <peter.chen@freescale.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Tested-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-03usb: kill DEBUG compile optionOliver Neukum
In the drivers that no longer need it, it is removed. It is removed from the Makefile. Drivers not fully converted to dynamic debug have it shifted down into the individual drivers. Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-14USB: EHCI: create per-TT bandwidth tablesAlan Stern
This patch continues the scheduling changes in ehci-hcd by adding a table to store the bandwidth allocation below each TT. This will speed up the scheduling code, as it will no longer need to read through the entire schedule to compute the bandwidth currently in use. Properly speaking, the FS/LS budget calculations should be done in terms of full-speed bytes per microframe, as described in the USB-2 spec. However the driver currently uses microseconds per microframe, and the scheduling code isn't robust enough at this point to change over. For the time being, we leave the calculations as they are. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-11USB: EHCI: use a bandwidth-allocation tableAlan Stern
This patch significantly changes the scheduling code in ehci-hcd. Instead of calculating the current bandwidth utilization by trudging through the schedule and adding up the times used by the existing transfers, we will now maintain a table holding the time used for each of 64 microframes. This will drastically speed up the bandwidth computations. In addition, it eliminates a theoretical bug. An isochronous endpoint may have bandwidth reserved even at times when it has no transfers listed in the schedule. The table will keep track of the reserved bandwidth, whereas adding up entries in the schedule would miss it. As a corollary, we can keep bandwidth reserved for endpoints even when they aren't in active use. Eventually the bandwidth will be reserved when a new alternate setting is installed; for now the endpoint's reservation takes place when its first URB is submitted. A drawback of this approach is that transfers with an interval larger than 64 microframes will have to be charged for bandwidth as though the interval was 64. In practice this shouldn't matter much; transfers with longer intervals tend to be rather short anyway (things like hubs or HID devices). Another minor drawback is that we will keep track of two different period and phase values: the actual ones and the ones used for bandwidth allocation (which are limited to 64). This adds only a small amount of overhead: 3 bytes for each endpoint. The patch also adds a new debugfs file named "bandwidth" to display the information stored in the new table. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-11USB: EHCI: create a "periodic schedule info" structAlan Stern
This patch begins the process of unifying the scheduling parameters that ehci-hcd uses for interrupt and isochronous transfers. It creates an ehci_per_sched structure, which will be stored in both ehci_qh and ehci_iso_stream structures, and will contain the common scheduling information needed for both. Initially we merely create the new structure and move some existing fields into it. Later patches will add more fields and utilize these structures in improved scheduling algorithms. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-11USB: EHCI: use consistent NO_FRAME valueAlan Stern
ehci-hcd is inconsistent in the sentinel values it uses to indicate that no frame number has been assigned for a periodic transfer. Some places it uses NO_FRAME (defined as 65535), other places it uses -1, and elsewhere it uses 9999. This patch defines a value for NO_FRAME which can fit in a 16-bit signed integer, and changes the code to use it everywhere. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-17USB: EHCI: handle isochronous underruns with taskletsAlan Stern
This patch updates the iso_stream_schedule() routine in ehci-sched.c to handle cases where an underrun causes an isochronous endpoint's queue to empty out, but the client driver wants to maintain synchronization with the device (i.e., the URB_ISO_ASAP flag is not set). This could not happen until recently, when ehci-hcd switched over to completing URBs in a tasklet. (This may seem like an unlikely case to worry about, but underruns are all too common with the snd-usb-audio driver, which doesn't use URB_ISO_ASAP.) As part of the fix, some URBs may need to be given back when they are submitted. This is necessary when the URB's scheduled slots all fall before the current value of ehci->last_iso_frame, and as an optimization we do it also when the slots all fall before the current frame number. As a second part of the fix, we may need to skip some but not all of an URB's packets. This is necessary when some of the URB's scheduled slots fall before the current value of ehci->last_iso_frame and some of them fall after the current frame number. A new field (first_packet) is added to struct ehci_iso_sched, to indicate how many packets should be skipped. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-30ehci: enable debugging code when CONFIG_DYNAMIC_DEBUG is setXenia Ragiadakou
The debugging code for ehci is enabled to run if the DEBUG flag is defined. This patch enables the debugging code also when the kernel is configured with dynamic debugging on. Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-30ehci: remove ehci_vdbg() verbose debugging statementsXenia Ragiadakou
This patch removes ehci_vdbg debugging statements from EHCI host controller driver because they produce too much information, lowering the signal to noise ratio when debugging, and because they are not used anymore. Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-13Merge tag 'usb-for-v3.12' of ↵Greg Kroah-Hartman
git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-next Felipe writes: usb: patches for v3.12 merge window All patches here have been pending on linux-usb and sitting in linux-next for a while now. The biggest things in this tag are: DWC3 learned proper usage of threaded IRQ handlers and now we spend very little time in hardirq context. MUSB now has proper support for BeagleBone and Beaglebone Black. Tegra's USB support also got quite a bit of love and is learning to use PHY layer and generic DT attributes. Other than that, the usual pack of cleanups and non-critical fixes follow. Signed-of-by: Felipe Balbi <balbi@ti.com> Conflicts: drivers/usb/gadget/udc-core.c drivers/usb/host/ehci-tegra.c drivers/usb/musb/omap2430.c drivers/usb/musb/tusb6010.c
2013-08-12USB: EHCI: improve interrupt qh unlinkMing Lei
ehci-hcd currently unlinks an interrupt QH when it becomes empty, that is, after its last URB completes. This works well because in almost all cases, the completion handler for an interrupt URB resubmits the URB; therefore the QH doesn't become empty and doesn't get unlinked. When we start using tasklets for URB completion, this scheme won't work as well. The resubmission won't occur until the tasklet runs, which will be some time after the completion is queued with the tasklet. During that delay, the QH will be empty and so will be unlinked unnecessarily. To prevent this problem, this patch adds a 5-ms time delay before empty interrupt QHs are unlinked. Most often, during that time the interrupt URB will be resubmitted and thus we can avoid unlinking the QH. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-12usb: host: add has_tdi_phy_lpm capability bitTuomas Tynkkynen
The has_hostpc capability bit indicates that the host controller has the HOSTPC register extensions, but at the same time enables clock disabling power saving features with the PHY Low Power Clock Disable (PHCD) bit. However, some host controllers have the HOSTPC extensions but don't support the low-power feature, so the PHCD bit must not be set on those controllers. Add a separate capability bit for the low-power feature instead, and change all existing users of has_hostpc to use this new capability bit. The idea for this commit is taken from an old 2012 commit that never got merged ("disociate chipidea PHY low power suspend control from hostpc") Inspired-by: Matthieu CASTET <matthieu.castet@parrot.com> Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Stephen Warren <swarren@nvidia.com> Reviewed-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
2013-06-17USB: EHCI: export ehci_handshake for ehci-hcd sub-driversManjunath Goudar
In order to split ehci-hcd.c into separate modules, handshake() must be exported. Rename the symbol to add an ehci_ prefix, to avoid any naming clashes. Signed-off-by: Manjunath Goudar <manjunath.goudar@linaro.org> [swarren, split Manjunath's patches more logically, limit this change to export just handshake()] Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-04-03EHCI: Quirk flag for port power handling on overcurrent.Christian Engelmayer
Commit 756aa6b3d536afe85e151138cb03a293998887b3 (ehci-hub: improved over-current recovery) added port power cycling on overcurrent indications as needed by the MPC8349 USB controller after resolving of the overcurrent situation in order to have the host state machine assert the correct port status again. Commit 81463c1d707186adbbe534016cd1249edeab0dac (EHCI: only power off port if over-current is active) solved a thus resulting issue of endless overcurrent changes in combination with the MAX4967 USB power supply chip that signals overcurrent when power is not enabled by only powering off a port if the overcurrent is currently active. Added quirks flag need_oc_pp_cycle in order to specify the needed behaviour as there is no common behaviour that can comply with both requirements. Activated the quirks handling for Freescale 83xx based boards. Signed-off-by: Christian Engelmayer <christian.engelmayer@frequentis.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-25USB: EHCI: improve end_unlink_async()Alan Stern
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>
2013-03-25USB: EHCI: convert singly-linked lists to list_headsAlan Stern
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>
2013-03-25USB: EHCI: split needs_rescan into two flagsAlan Stern
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>
2013-01-22USB: EHCI: add a name for the platform-private fieldAlan Stern
This patch (as1642) adds an ehci->priv field for private use by EHCI platform drivers. The space was provided some time ago, but it didn't have a name. Until now none of the platform drivers has used this private space, but that's about to change in the next patch of this series. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-22USB: EHCI: Move definition of EHCI_STATS to ehci.hRoger Quadros
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>
2012-11-11USB: EHCI: miscellaneous cleanups for the library conversionAlan Stern
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>
2012-11-01USB: EHCI: prepare to make ehci-hcd a library moduleAlan Stern
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>
2012-10-31USB: EHCI: remove unused Link Power Management codeAlan Stern
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>
2012-10-24USB: EHCI: make ehci_read_frame_index platform independentAlan Stern
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>
2012-10-24USB: EHCI: move logging macros to ehci.hAlan Stern
In preparation for splitting the ehci-hcd driver into a core library and separate platform-specific driver modules, this patch (as1616) moves the console logging macros from ehci-dbg.c to ehci.h, where they will be available to the platform drivers. 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>
2012-10-22EHCI: use the isochronous scheduling thresholdAlan Stern
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>
2012-10-22EHCI: improved logic for isochronous schedulingAlan Stern
This patch (as1608) reworks the logic used by ehci-hcd for scheduling isochronous transfers. Now the modular calculations are all based on a window that starts at the last frame scanned for isochronous completions. No transfer descriptors for any earlier frames can possibly remain on the schedule, so there can be no confusion from schedule wrap-around. This removes the need for a "slop" region of arbitrary size. There's no need to check for URBs that are longer than the schedule length. With the old code they could throw things off by wrapping around and appearing to end in the near future rather than the distant future. Now such confusion isn't possible, and the existing test for submissions that extend too far into the future will also catch those that exceed the schedule length. (But there still has to be an initial test to handle the case where the schedule already extends as far into the future as possible.) Delays caused by IRQ latency won't confuse the algorithm unless they are ridiculously long (over 250 ms); they will merely reduce how far into the future new transfers can be scheduled. A few people have reported problems caused by delays of 50 ms or so. Now instead of failing completely, isochronous transfers will experience a brief glitch and then continue normally. (Whether this is truly a good thing is debatable. A latency as large as 50 ms generally indicates a bug is present, and complete failure of audio or video transfers draws people's attention pretty vividly. Making the transfers more robust also makes it easier for such bugs to remain undetected.) Finally, ehci->next_frame is renamed to ehci->last_iso_frame, because that better describes what it is: the last frame to have been scanned for isochronous completions. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16USB: EHCI: resolve some unlikely racesAlan Stern
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>
2012-07-16USB: EHCI: simplify isochronous scanningAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for the I/O watchdogAlan Stern
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>
2012-07-16USB: EHCI: always scan each interrupt QHAlan Stern
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>
2012-07-16USB: EHCI: don't lose events during a scanAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for unlinking empty async QHsAlan Stern
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>
2012-07-16USB: EHCI: unlink multiple async QHs togetherAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for the IAA watchdogAlan Stern
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>
2012-07-16USB: EHCI: don't refcount iso_stream structuresAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for (s)iTD deallocationAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for controller deathAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for interrupt QH unlinkAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for async scheduleAlan Stern
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>
2012-07-16USB: EHCI: use hrtimer for the periodic scheduleAlan Stern
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>
2012-07-16USB: EHCI: introduce high-res timerAlan Stern
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>
2012-07-16USB: EHCI: add new root-hub state: STOPPINGAlan Stern
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>
2012-07-16USB: EHCI: add pointer to end of async-unlink listAlan Stern
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>
2012-07-16USB: EHCI: rename "reclaim"Alan Stern
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>
2012-07-16USB: EHCI: add symbolic constants for QHsAlan Stern
This patch (as1568) introduces symbolic constants for some of the less-frequently used bitfields in the QH structure. This makes the code a little easier to read and understand. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-07-16USB: EHCI: don't refcount QHsAlan Stern
This patch (as1567) removes ehci-hcd's reference counting of QH structures. It's not necessary to refcount these things because they always get deallocated at exactly one spot in ehci_endpoint_disable() (except for two special QHs, ehci->async and ehci->dummy) and are never used again. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-13USB: move transceiver from ehci_hcd and ohci_hcd to hcd and rename it as phyRichard Zhao
- to decrease redundant since both ehci_hcd and ohci_hcd have the same variable - it helps access phy in usb core code - phy is more meaningful than transceiver Signed-off-by: Richard Zhao <richard.zhao@freescale.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09EHCI: keep track of ports being resumed and indicate in hub_status_dataAlan Stern
This patch (as1537) adds a bit-array to ehci-hcd for keeping track of which ports are undergoing a resume transition. If any of the bits are set when ehci_hub_status_data() is called, the routine will return a nonzero value even if no ports have any status changes pending. This will allow usbcore to handle races between root-hub suspend and port wakeup. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Sarah Sharp <sarah.a.sharp@linux.intel.com> CC: Chen Peter-B29397 <B29397@freescale.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-13usb: otg: Rename otg_transceiver to usb_phyHeikki Krogerus
This is the first step in separating USB transceivers from USB OTG utilities. Includes fixes to IMX code from Sascha Hauer. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Pavankumar Kondeti <pkondeti@codeaurora.org> Acked-by: Li Yang <leoli@freescale.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Igor Grinberg <grinberg@compulab.co.il> Reviewed-by: Marek Vasut <marek.vasut@gmail.com> Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-10-18EHCI: workaround for MosChip controller bugAlan Stern
This patch (as1489) works around a hardware bug in MosChip EHCI controllers. Evidently when one of these controllers increments the frame-index register, it changes the three low-order bits (the microframe counter) before changing the higher order bits (the frame counter). If the register is read at just the wrong time, the value obtained is too low by 8. When the appropriate quirk flag is set, we work around this problem by reading the frame-index register a second time if the first value's three low-order bits are all 0. This gives the hardware a chance to finish updating the register, yielding the correct value. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Jason N Pitt <jpitt@fhcrc.org> CC: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>