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path: root/drivers/usb/host/ehci-q.c
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2011-08-22USB: EHCI: remove usages of hcd->stateAlan Stern
This patch (as1483) improves the ehci-hcd driver family by getting rid of the reliance on the hcd->state variable. It has no clear owner and it isn't protected by the usual HCD locks. In its place, the patch adds a new, private ehci->rh_state field to record the state of the root hub. Along the way, the patch removes a couple of lines containing redundant assignments to the state variable. Also, the QUIESCING state simply gets changed to the RUNNING state, because the driver doesn't make any distinction between them. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-07-19EHCI: fix direction handling for interrupt data togglesAlan Stern
This patch (as1480) fixes a rather obscure bug in ehci-hcd. The qh_update() routine needs to know the number and direction of the endpoint corresponding to its QH argument. The number can be taken directly from the QH data structure, but the direction isn't stored there. The direction is taken instead from the first qTD linked to the QH. However, it turns out that for interrupt transfers, qh_update() gets called before the qTDs are linked to the QH. As a result, qh_update() computes a bogus direction value, which messes up the endpoint toggle handling. Under the right combination of circumstances this causes usb_reset_endpoint() not to work correctly, which causes packets to be dropped and communications to fail. Now, it's silly for the QH structure not to have direct access to all the descriptor information for the corresponding endpoint. Ultimately it may get a pointer to the usb_host_endpoint structure; for now, adding a copy of the direction flag solves the immediate problem. This allows the Spyder2 color-calibration system (a low-speed USB device that sends all its interrupt data packets with the toggle set to 0 and hance requires constant use of usb_reset_endpoint) to work when connected through a high-speed hub. Thanks to Graeme Gill for supplying the hardware that allowed me to track down this bug. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Graeme Gill <graeme@argyllcms.com> CC: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-07-08USB: EHCI: go back to using the system clock for QH unlinksAlan Stern
This patch (as1477) fixes a problem affecting a few types of EHCI controller. Contrary to what one might expect, these controllers automatically stop their internal frame counter when no ports are enabled. Since ehci-hcd currently relies on the frame counter for determining when it should unlink QHs from the async schedule, those controllers run into trouble: The frame counter stops and the QHs never get unlinked. Some systems have also experienced other problems traced back to commit b963801164618e25fbdc0cd452ce49c3628b46c8 (USB: ehci-hcd unlink speedups), which made the original switch from using the system clock to using the frame counter. It never became clear what the reason was for these problems, but evidently it is related to use of the frame counter. To fix all these problems, this patch more or less reverts that commit and goes back to using the system clock. But this can't be done cleanly because other changes have since been made to the scan_async() subroutine. One of these changes involved the tricky logic that tries to avoid rescanning QHs that have already been seen when the scanning loop is restarted, which happens whenever an URB is given back. Switching back to clock-based unlinks would make this logic even more complicated. Therefore the new code doesn't rescan the entire async list whenever a giveback occurs. Instead it rescans only the current QH and continues on from there. This requires the use of a separate pointer to keep track of the next QH to scan, since the current QH may be unlinked while the scanning is in progress. That new pointer must be global, so that it can be adjusted forward whenever the _next_ QH gets unlinked. (uhci-hcd uses this same trick.) Simplification of the scanning loop removes a level of indentation, which accounts for the size of the patch. The amount of code changed is relatively small, and it isn't exactly a reversion of the b963801164 commit. This fixes Bugzilla #32432. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@kernel.org> Tested-by: Matej Kenda <matejken@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-05-17EHCI: don't rescan interrupt QHs needlesslyAlan Stern
This patch (as1466) speeds up processing of ehci-hcd's periodic list. The existing code will pointlessly rescan an interrupt endpoint queue each time it encounters the queue's QH in the periodic list, which can happen quite a few times if the endpoint's period is low. On some embedded systems, this useless overhead can waste so much time that the driver falls hopelessly behind and loses events. The patch introduces a "periodic_stamp" variable, which gets incremented each time scan_periodic() runs and each time the scan advances to a new frame. If the corresponding stamp in an interrupt QH is equal to the current periodic_stamp, we assume the QH has already been scanned and skip over it. Otherwise we scan the QH as usual, and if none of its URBs have completed then we store the current periodic_stamp in the QH's stamp, preventing it from being scanned again. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-19Merge 2.6.39-rc4 into usb-nextGreg Kroah-Hartman
This is needed to help resolve some xhci issues and other minor differences. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-13USB: ehci: add workaround for Synopsys HC bugGabor Juhos
A Synopsys USB core used in various SoCs has a bug which might cause that the host controller not issuing ping. When software uses the Doorbell mechanism to remove queue heads, the host controller still has references to the removed queue head even after indicating an Interrupt on Async Advance. This happens if the last executed queue head's Next Link queue head is removed. Consequences of the defect: The Host controller fetches the removed queue head, using memory that would otherwise be deallocated.This results in incorrect transactions on both the USB and system memory. This may result in undefined behavior. Workarounds: 1) If no queue head is active (no Status field's Active bit is set) after removing the queue heads, the software can write one of the valid queue head addresses to the ASYNCLISTADDR register and deallocate the removed queue head's memory after 2 microframes. If one or more of the queue heads is active (the Active bit is set in the Status field) after removing the queue heads, the software can delay memory deallocation after time X, where X is the time required for the Host Controller to go through all the queue heads once. X varies with the number of queue heads and the time required to process periodic transactions: if more periodic transactions must be performed, the Host Controller has less time to process asynchronous transaction processing. 2) Do not use the Doorbell mechanism to remove the queue heads. Disable the Asynchronous Schedule Enable bit instead. The bug has been discussed on the linux-usb-devel mailing-list four years ago, the original thread can be found here: http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg45345.html This patch implements the first workaround as suggested by David Brownell. The built-in USB host controller of the Atheros AR7130/AR7141/AR7161 SoCs requires this to work properly. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-13USB: EHCI: unlink unused QHs when the controller is stoppedAlan Stern
This patch (as1458) fixes a problem affecting ultra-reliable systems: When hardware failover of an EHCI controller occurs, the data structures do not get released correctly. This is because the routine responsible for removing unused QHs from the async schedule assumes the controller is running properly (the frame counter is used in determining how long the QH has been idle) -- but when a failover causes the controller to be electronically disconnected from the PCI bus, obviously it stops running. The solution is simple: Allow scan_async() to remove a QH from the async schedule if it has been idle for long enough _or_ if the controller is stopped. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-and-Tested-by: Dan Duval <dan.duval@stratus.com> CC: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-23ehci-hcd: Bug fix: don't set a QH's Halt bitAlan Stern
This patch (as1453) fixes a long-standing bug in the ehci-hcd driver. There is no need to set the Halt bit in the overlay region for an unlinked or blocked QH. Contrary to what the comment says, setting the Halt bit does not cause the QH to be patched later; that decision (made in qh_refresh()) depends only on whether the QH is currently pointing to a valid qTD. Likewise, setting the Halt bit does not prevent completions from activating the QH while it is "stopped"; they are prevented by the fact that qh_completions() temporarily changes qh->qh_state to QH_STATE_COMPLETING. On the other hand, there are circumstances in which the QH will be reactivated _without_ being patched; this happens after an URB beyond the head of the queue is unlinked. Setting the Halt bit will then cause the hardware to see the QH with both the Active and Halt bits set, an invalid combination that will prevent the queue from advancing and may even crash some controllers. Apparently the only reason this hasn't been reported before is that unlinking URBs from the middle of a running queue is quite uncommon. However Test 17, recently added to the usbtest driver, does exactly this, and it confirms the presence of the bug. In short, there is no reason to set the Halt bit for an unlinked or blocked QH, and there is a very good reason not to set it. Therefore the code that sets it is removed. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Andiry Xu <andiry.xu@amd.com> CC: David Brownell <david-b@pacbell.net> CC: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-04USB: EHCI: Rearrange EHCI_URB_TRACE code to avoid GCC-4.6 warnings.David Daney
With pre-release GCC-4.6, we get a 'set but not used' warning when EHCI_URB_TRACE is not set because we set the qtd variable without using it. Rearrange the statements so that we only set qtd if it will be used. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10USB: convert usb_hcd bitfields into atomic flagsAlan Stern
This patch (as1393) converts several of the single-bit fields in struct usb_hcd to atomic flags. This is for safety's sake; not all CPUs can update bitfield values atomically, and these flags are used in multiple contexts. The flag fields that are set only during registration or removal can remain as they are, since non-atomic accesses at those times will not cause any problems. (Strictly speaking, the authorized_default flag should become atomic as well. I didn't bother with it because it gets changed only via sysfs. It can be done later, if anyone wants.) Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20USB: Change the scatterlist type in struct urbMatthew Wilcox
Change the type of the URB's 'sg' pointer from a usb_sg_request to a scatterlist. This allows drivers to submit scatter-gather lists without using the usb_sg_wait() interface. It has the added benefit of removing the typecasts that were added as part of patch as1368 (and slightly decreasing the number of pointer dereferences). Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Reviewed-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-01-20USB: EHCI: fix handling of unusual interrupt intervalsAlan Stern
This patch (as1320) fixes two problems related to interrupt-URB scheduling in ehci-hcd. URBs with an interval of 2 or 4 microframes aren't handled. For the time being, the patch reduces to interval to 1 uframe. URBs are constrained to have an interval no larger than 1024 frames by usb_submit_urb(). But some EHCI controllers allow use of a schedule as short as 256 frames; for these controllers we may have to decrease the interval to the actual schedule length. The second problem isn't very significant since few devices expose interrupt endpoints with an interval larger than 256 frames. But the first problem is critical; it will prevent the kernel from working with devices having interrupt intervals of 2 or 4 uframes. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@kernel.org> Tested-by: Glynn Farrow <farrowg@sg.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-11USB: EHCI: add native scatter-gather supportAlan Stern
This patch (as1300) adds native scatter-gather support to ehci-hcd. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-11-30USB: EHCI: don't send Clear-TT-Buffer following a STALLAlan Stern
This patch (as1304) fixes a regression in ehci-hcd. Evidently some hubs don't handle Clear-TT-Buffer requests correctly, so we should avoid sending them when they don't appear to be absolutely necessary. The reported symptom is that output on a downstream audio device cuts out because the hub stops relaying isochronous packets. The patch prevents Clear-TT-Buffer requests from being sent following a STALL handshake. In theory a STALL indicates either that the downstream device sent a STALL or that no matching TT buffer could be found. In either case, the transfer is completed and the TT buffer does not remain busy, so it doesn't need to be cleared. Also, the patch fixes a minor flaw in the code that actually sends the Clear-TT-Buffer requests. Although the pipe direction isn't really used for control transfers, it should be a Send rather than a Receive. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Javier Kohen <jkohen@users.sourceforge.net> CC: David Brownell <david-b@pacbell.net> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: EHCI: change deschedule logic for interrupt QHsAlan Stern
This patch (as1281) changes the way ehci-hcd deschedules interrupt QHs, copying the approach used for async QHs. The caller is no longer responsible for rescheduling the QH if its queue is non-empty; instead the reschedule is done directly by intr_deschedule(), after calling qh_completions(). This is exactly the same as how end_unlink_async() works. ehci_urb_dequeue() and intr_deschedule() now correctly handle the case where they are called while another interrupt URB for the same QH is being given back. This was a surprisingly large blind spot. And scan_periodic() now respects the new needs_rescan flag. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: EHCI: rescan the queue after an unlinkAlan Stern
This patch (as1280) fixes an obscure bug in ehci-hcd's dequeuing logic for async URBs. If a later URB is unlinked and the completion routine unlinks an earlier URB, then the earlier URB won't be given back in a timely manner because the endpoint queue isn't rescanned as it should be. Similar bugs occur if an endpoint is reset or a halt is cleared while a completion routine is running, because the subroutines don't test for the COMPLETING state. All these problems are solved by adding a new needs_rescan flag to the ehci_qh structure. If the flag is set while scanning through an idle QH, the scan will be repeated. If the QH isn't idle then an unlink cycle will be initiated, and the proper action will be taken when it becomes idle. Also, an unnecessary test is removed from qh_link_async(): That routine is never called if the QH's state isn't IDLE. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: EHCI: split ehci_qh into hw and sw partsAlek Du
The ehci_qh structure merged hw and sw together which is not good: 1. More and more items are being added into ehci_qh, the ehci_qh software part are unnecessary to be allocated in DMA qh_pool. 2. If HCD has local SRAM, the sw part will consume it too, and it won't bring any benefit. 3. For non-cache-coherence system, the entire ehci_qh is uncachable, actually we only need the hw part to be uncacheable. Spliting them will let the sw part to be cacheable. Signed-off-by: Alek Du <alek.du@intel.com> Cc: David Brownell <dbrownell@users.sourceforge.net> CC: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-08-07USB: EHCI: fix counting of transaction error retriesAlan Stern
This patch (as1274) simplifies the counting of transaction-error retries. Now we will count up from 0 to QH_XACTERR_MAX instead of down from QH_XACTERR_MAX to 0. The patch also fixes a small bug: qh->xacterr was not getting initialized for interrupt endpoints. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Matthijs Kooijman <matthijs@stdin.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-08-07USB: EHCI: fix two new bugs related to Clear-TT-BufferAlan Stern
This patch (as1273) fixes two(!) bugs introduced by the new Clear-TT-Buffer implementation in ehci-hcd. It is now possible for an idle QH to have some URBs on its queue -- this will happen if a Clear-TT-Buffer is pending for the QH's endpoint. Consequently we should not issue a warning when someone tries to unlink an URB from an idle QH; instead we should process the request immediately. The refcounts for QHs could get messed up, because submit_async() would increment the refcount when calling qh_link_async() and qh_link_async() would then refuse to link the QH into the schedule if a Clear-TT-Buffer was pending. Instead we should increment the refcount only when the QH actually is added to the schedule. The current code tries to be clever by leaving the refcount alone if an unlink is immediately followed by a relink; the patch changes this to an unconditional decrement and increment (although they occur in the opposite order). Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> Tested-by: Manuel Lauss <manuel.lauss@gmail.com> Tested-by: Matthijs Kooijman <matthijs@stdin.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12USB: EHCI: check for STALL before other errorsAlan Stern
This patch (as1257) revises the way ehci-hcd detects STALLs. The logic is a little peculiar because there's no hardware status bit specifically meant to indicate a STALL. You just have to guess that a STALL was received if the BABBLE bit (which is fatal) isn't set and the transfer stopped before all its retries were used up. The existing code doesn't do this properly, because it tests for MMF (Missed MicroFrame) and DBE (Data Buffer Error) before testing the retry counter. Thus, if a transaction gets either MMF or DBE the corresponding flag is set and the transaction is retried. If the second attempt receives a STALL then -EPIPE is the correct return value. But the existing code would see the MMF or DBE flag instead and return -EPROTO, -ENOSR, or -ECOMM. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12USB: EHCI: use the new clear_tt_buffer interfaceAlan Stern
This patch (as1256) changes ehci-hcd and all the other drivers in the EHCI family to make use of the new clear_tt_buffer callbacks. When a Clear-TT-Buffer request is in progress for a QH, the QH is not allowed to be linked into the async schedule until the request is finished. At that time, if there are any URBs queued for the QH, it is linked into the async schedule. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12USB: fix the clear_tt_buffer interfaceAlan Stern
This patch (as1255) updates the interface for calling usb_hub_clear_tt_buffer(). Even the name of the function is changed! When an async URB (i.e., Control or Bulk) going through a high-speed hub to a non-high-speed device is cancelled or fails, the hub's Transaction Translator buffer may be left busy still trying to complete the transaction. The buffer has to be cleared; that's what usb_hub_clear_tt_buffer() does. It isn't safe to send any more URBs to the same endpoint until the TT buffer is fully clear. Therefore the HCD needs to be told when the Clear-TT-Buffer request has finished. This patch adds a callback method to struct hc_driver for that purpose, and makes the hub driver invoke the callback at the proper time. The patch also changes a couple of names; "hub_tt_kevent" and "tt.kevent" now look rather antiquated. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12USB: EHCI: update toggle state for linked QHsAlan Stern
This is an update to the "usb-ehci-update-toggle-state-for-linked-qhs" patch. Since an HCD's endpoint_reset method can be called in interrupt context, it mustn't assume that interrupts are enabled or that it can sleep. So we revert to the original way of refreshing QHs' toggle bits. Now the endpoint_reset method merely clears the toggle flag in the device structure (as was done before) and starts an async QH unlink. When the QH is linked again, after the unlink finishes and an URB is queued, the qh_refresh() routine will update the QH's toggle bit. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: David <david@unsolicited.net> CC: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15USB: EHCI: update toggle state for linked QHsAlan Stern
This patch (as1245) fixes a bug in ehci-hcd. When an URB is queued for an endpoint whose QH is already in the LINKED state, the QH doesn't get refreshed. As a result, if usb_clear_halt() was called during the time that the QH was linked but idle, the data toggle value in the QH doesn't get reset. The symptom is that after a clear_halt, data gets lost and transfers time out. This problem is starting to show up now because the "ehci-hcd unlink speedups" patch causes QHs with no queued URBs to remain linked for a suitable time. The patch utilizes the new endpoint_reset mechanism to fix the problem. When an endpoint is reset, the new method forcibly unlinks the QH (if necessary) and safely updates the toggle value. This allows qh_update() to be simplified and avoids using usb_device's toggle bits in a rather unintuitive way. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> Tested-by: David <david@unsolicited.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24USB: fix ehci printk formatsRandy Dunlap
Fix ehci printk formats: drivers/usb/host/ehci-q.c:351: warning: format '%d' expects type 'int', but argument 4 has type 'size_t' drivers/usb/host/ehci-q.c:351: warning: format '%d' expects type 'int', but argument 5 has type 'size_t' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-24USB: EHCI: add software retry for transaction errorsAlan Stern
This patch (as1204) adds a software retry mechanism to ehci-hcd. It gets invoked when the driver encounters transaction errors on an asynchronous endpoint. On many systems, hardware deficiencies cause such errors to occur if one device is unplugged while the host is communicating with another device. With the patch, the failed transactions are retried and generally succeed the second or third time through. This is based on code originally written by Koichiro Saito. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested by: Koichiro Saito <Saito.Koichiro@adniss.jp> CC: David Brownell <david-b@pacbell.net> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-03-17USB: EHCI: expedite unlinks when the root hub is suspendedAlan Stern
This patch (as1225) fixes a bug in ehci-hcd. The condition for whether unlinked QHs can become IDLE should not be that the controller is halted, but rather that the controller isn't running. In other words when the root hub is suspended, the hardware doesn't own any QHs. This fixes a problem that can show up during hibernation: If a QH is only partially unlinked when the root hub is frozen, then when the root hub is thawed the QH won't be in the IDLE state. As a result it can't be used properly for new URB submissions. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: Brandon Philips <brandon@ifup.org> Tested-by: Brandon Philips <brandon@ifup.org> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-07list.h: Add list_splice_tail() and list_splice_tail_init()Luis R. Rodriguez
If you are using linked lists for queues list_splice() will not do what you would expect even if you use the elements passed reversed. We need to handle these differently. We add list_splice_tail() and list_splice_tail_init(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-07-21USB: ehci-hcd unlink speedupsDavid Brownell
This patch fixes some performance bugs observed with some workloads when unlinking EHCI queue header (QH) descriptors from the async ring (control/bulk schedule). The mechanism intended to defer unlinking an empty QH (so there is no penalty in common cases where it's quickly reused) was not working as intended. Sometimes the unlink was scheduled: - too quickly ... which can be a *strong* negative effect, since that QH becomes unavailable for immediate re-use; - too slowly ... wasting DMA cycles, usually a minor issue except for increased bus contention and power usage; Plus there was an extreme case of "too slowly": a logical error in the IAA watchdog-timer conversion meant that sometimes the unlink never got scheduled. The fix replaces a simple counter with a timestamp derived from the controller's 8 KHz microframe counter, and adjusts the timer usage for some issues associated with HZ being less than 8K. (Based on a patch originally by Alan Stern, and good troubleshooting from Leonid.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Leonid <leonidv11@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-28drivers/usb annotations and fixesAl Viro
* endianness annotations * endianness fixes * missing get_unaligned/put_unaligned It's pretty much all over the place, changes to different files are independent. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Serial-parts-Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-24USB: replace remaining __FUNCTION__ occurrencesHarvey Harrison
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-24USB: ehci: qh_completions cleanup and bugfixDavid Brownell
Simplify processing of completed qtds, and correct handling of short reads, by removing two state variables: - "qtd_status" wasn't needed. The current URB's status is either OK (-EINPROGRESS) or some fault status. Once a fault appears, the queue halts and any later QTDs are immediately removed, so no temporary status is needed. (Or for typical short reads, it's not treated as a fault, so no queue halt is needed.) - "do_status" was erroneous. Because of how the queue is set up, short control reads can (and should!) be treated like full size reads, and cleaned up the usual way. The status stage will be executed transparently, and usbcore handles the choice of whether to report this status as unexected. The "do_status" problem caused a rather perplexing timing-dependent problem with usbtest case 10. Sometimes it would make the controller skip a dozen transactions while (wrongly) trying to clean up after a short transfer. Fortunately, removing a dcache contention issue made this become trivial to reproduce (on one test rig), so enough clues finally presented themselves ... I think this has been around for a very long time, but was worsened by recent urb->status changes. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-24USB: ehci: qh/qtd cleanup commentsDavid Brownell
Provide better comments about qh_completions() and QTD handling. That code can be *VERY* confusing, since it's evolved over a few years to cope with both hardware races and silicon quirks. Remove two unlikely() annotations that match the GCC defaults (and are thus pointless); add an "else" to highlight code flow. This patch doesn't change driver behavior. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-24USB: ehci tolerates some buggy devicesDavid Brownell
This teaches EHCI how to to work around bugs in certain high speed devices, by accomodating "bulk" packets that exceed the 512 byte constant value required by the USB 2.0 specification. (Have a look at section 5.8.3, paragraphs 1 and 3.) It also makes the descriptor parsing code warn when it encounters such bugs. (We've had reports of maybe two or three such devices, all pretty recent.) Such devices are nonconformant. The proper fix is have the vendors of those devices do the simple, obvious, and correct thing ... which will let them be used with USB hosts that don't have workarounds for this particular vendor bug. But unless/until they do, we can at least have one of the high speed HCDs work with such buggy devices. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-03-04USB: ehci: handle large bulk URBs correctly (again)Misha Zhilin
USB: ehci: Fixes completion for multi-qtd URB the short read case When use of urb->status in the EHCI driver was reworked last August (commit 14c04c0f88f228fee1f412be91d6edcb935c78aa), a bug was inserted in the handling of early completion for bulk transactions that need more than one qTD (e.g. more than 20KB in one URB). This patch resolves that problem by ensuring that the early completion status is preserved until the URB is handed back to its submitter, instead of resetting it after each qTD. Signed-off-by: Misha Zhilin <misha@epiphan.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01USB: ehci potential oops fix on ARC/TDI coresDavid Brownell
Kernel bugzilla entry #9569 reports a potential OOPS in some code supporting the integrated root hub TT support used on ARC/TDI derived cores. (This seems to have been a longstanding issue.) This patch cleans up usage of urb->dev->tt to avoid that potential oops and also fixes some overly long lines. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01USB: EHCI: add separate IAA watchdog timerAlan Stern
This patch (as1028) was mostly written by David Brownell; I made only a few changes (extra log info and a small bug fix -- which might account for why David's version had to be reverted). It adds a new watchdog timer to the ehci-hcd driver to be used exclusively for detecting lost or missing IAA notifications. Previously a shared timer had been used, which may have led to some problems as reported by Christian Hoffmann. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12USB: Eliminate urb->status usage!Alan Stern
This patch (as979) removes the last vestiges of urb->status from the host controller drivers and the root-hub emulator. Now the field doesn't get set until just before the URB's completion routine is called. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> CC: Olav Kongas <ok@artecdesign.ee> CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com> CC: Tony Olech <tony.olech@elandigitalsystems.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12USB: reorganize urb->status use in ehci-hcdAlan Stern
This patch (as974) reorganizes the way ehci-hcd sets urb->status. It now keeps the information in a local variable until the last moment. The patch also simplifies the handling of -EREMOTEIO, since the only use of that code is to set the do_status flag. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12USB: add urb->unlinked fieldAlan Stern
This patch (as970) adds a new urb->unlinked field, which is used to store the status of unlinked URBs since we can't use urb->status for that purpose any more. To help simplify the HCDs, usbcore will check urb->unlinked before calling the completion handler; if the value is set it will automatically override the status reported by the HCD. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> CC: Olav Kongas <ok@artecdesign.ee> CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com> CC: Tony Olech <tony.olech@elandigitalsystems.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12USB: centralize -EREMOTEIO handlingAlan Stern
This patch (as969) continues the ongoing changes to the way HCDs report URB statuses. The programming interface has been simplified by making usbcore responsible for clearing urb->hcpriv and for setting -EREMOTEIO status when an URB with the URB_SHORT_NOT_OK flag ends up as a short transfer. By moving the work out of the HCDs, this removes a fair amount of repeated code. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> CC: Olav Kongas <ok@artecdesign.ee> CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com> CC: Tony Olech <tony.olech@elandigitalsystems.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12USB: make HCDs responsible for managing endpoint queuesAlan Stern
This patch (as954) implements a suggestion of David Brownell's. Now the host controller drivers are responsible for linking and unlinking URBs to/from their endpoint queues. This eliminates the possiblity of strange situations where usbcore thinks an URB is linked but the HCD thinks it isn't. It also means HCDs no longer have to check for URBs being dequeued before they were fully enqueued. In addition to the core changes, this requires changing every host controller driver and the root-hub URB handler. For the most part the required changes are fairly small; drivers have to call usb_hcd_link_urb_to_ep() in their urb_enqueue method, usb_hcd_check_unlink_urb() in their urb_dequeue method, and usb_hcd_unlink_urb_from_ep() before giving URBs back. A few HCDs make matters more complicated by the way they split up the flow of control. In addition some method interfaces get changed. The endpoint argument for urb_enqueue is now redundant so it is removed. The unlink status is required by usb_hcd_check_unlink_urb(), so it has been added to urb_dequeue. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: David Brownell <david-b@pacbell.net> CC: Olav Kongas <ok@artecdesign.ee> CC: Tony Olech <tony.olech@elandigitalsystems.com> CC: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-08-20Revert "USB: EHCI cpufreq fix"Linus Torvalds
This reverts commit 196705c9bbc03540429b0f7cf9ee35c2f928a534. It was reported to cause a regression by Daniel Exner, and Arjan van de Ven points out that we actually already have infrastructure in place for setting limits on acceptable DMA latency that would be the much more correct fix for the problem with some Broadcom EHCI controllers. Fixed up trivial conflicts due to the changes to support big-endian host controller descriptors in drivers/usb/host/{ehci-sched.c,ehci.h}. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-12USB: EHCI support for big-endian descriptorsStefan Roese
This patch implements supports for EHCI controllers whose in-memory data structures are represented in big-endian format. This is needed (unfortunately) for the AMCC PPC440EPx SoC EHCI controller; the EHCI spec doesn't specify little-endian format, although that's what most other implementations use. The guts of the patch are to introduce the hc32 type and change all references from le32 to hc32. All access routines are converted from cpu_to_le32(...) to cpu_to_hc32(ehci, ...) and similar for the other "direction". (This is the same approach used with OHCI.) David fixed: Whitespace fixes; refresh against ehci cpufreq patch; move glue for that PPC driver to the patch adding it; fix free symbol capture bugs in modified "constant" macros; and make "hc32" etc be "le32" unless we really need the BE options, so "sparse" can do some real good. Signed-off-by: Stefan Roese <sr@denx.de> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12USB: EHCI cpufreq fixStuart_Hayes@Dell.com
EHCI controllers that don't cache enough microframes can get MMF errors when CPU frequency changes occur between the start and completion of split interrupt transactions, due to delays in reading main memory (caused by CPU cache snoop delays). This patch adds a cpufreq notifier to the EHCI driver that will inactivate split interrupt transactions during frequency transitions. It was tested on Intel ICH7 and Serverworks/Broadcom HT1000 EHCI controllers. Signed-off-by: Stuart Hayes <stuart_hayes@dell.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-07USB: Implement support for EHCI with big endian MMIOBenjamin Herrenschmidt
This patch implements supports for EHCI controllers whose MMIO registers are big endian and enables that functionality for the Toshiba SCC chip. It does _not_ add support for big endian in-memory data structures as this is not needed for that chip and I hope it will never be. The guts of the patch are to convert readl(...) to ehci_readl(ehci, ...) and similarly for register writes. Signed-off-by: Kou Ishizaki <kou.ishizaki@toshiba.co.jp> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Geoff Levand <geoffrey.levand@am.sony.com> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-17USB: revert EHCI VIA workaround patchGreg Kroah-Hartman
This reverts 26f953fd884ea4879585287917f855c63c6b2666 which caused resume problems on the mac mini. Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-09-27USB: EHCI update VIA workaroundDavid Brownell
This revamps handling of the hardware "async advance" IRQ, and its watchdog timer. Basically it dis-entangles that important timeout from the others, simplifying the associated state and code to make it more robust. This reportedly improves behavior of EHCI on some systems with VIA chips, and AFAIK won't affect non-VIA hardware. VIA systems need this code to recover from silcon bugs whereby the "async advance" IRQ isn't issued. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-09-27USB: EHCI whitespace fixes (cosmetic)David Brownell
[ ... when you have an editor set to remind you of whitespace bugs ... ] Cosmetic EHCI changes: remove end-of-line whitespace, spaces before tabs. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>