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path: root/drivers/usb/host/xhci-ring.c
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2021-05-13xhci: Fix giving back cancelled URBs even if halted endpoint can't resetMathias Nyman
Commit 9ebf30007858 ("xhci: Fix halted endpoint at stop endpoint command completion") in 5.12 changes how cancelled URBs are given back. To cancel a URB xhci driver needs to stop the endpoint first. To clear a halted endpoint xhci driver needs to reset the endpoint. In rare cases when an endpoint halt (error) races with a endpoint stop we need to clear the reset before removing, and giving back the cancelled URB. The above change in 5.12 takes care of this, but it also relies on the reset endpoint completion handler to give back the cancelled URBs. There are cases when driver refuses to queue reset endpoint commands, for example when a link suddenly goes to an inactive error state. In this case the cancelled URB is never given back. Fix this by giving back the URB in the stop endpoint if queuing a reset endpoint command fails. Fixes: 9ebf30007858 ("xhci: Fix halted endpoint at stop endpoint command completion") CC: <stable@vger.kernel.org> # 5.12 Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210512080816.866037-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-06xhci: prevent double-fetch of transfer and transfer event TRBsMathias Nyman
The same values are parsed several times from transfer and event TRBs by different functions in the same call path, all while processing one transfer event. As the TRBs are in DMA memory and can be accessed by the xHC host we want to avoid this to prevent double-fetch issues. To resolve this pass the already parsed values to the different functions in the path of parsing a transfer event Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210406070208.3406266-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23USB: xhci: drop workaround for forced irq threadingJohan Hovold
Force-threaded interrupt handlers used to run with interrupts enabled, something which could lead to deadlocks in case a threaded handler shared a lock with code running in hard interrupt context (e.g. timer callbacks) and did not explicitly disable interrupts. Since commit 81e2073c175b ("genirq: Disable interrupts for force threaded handlers") interrupt handlers always run with interrupts disabled on non-RT so that drivers no longer need to do handle forced threading ("threadirqs"). Drop the now obsolete workaround added by commit 63aea0dbab90 ("USB: xhci: fix lock-inversion problem"). Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://lore.kernel.org/r/20210322111140.32056-1-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-15Merge 5.12-rc3 into usb-nextGreg Kroah-Hartman
We want the USB fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-11usb: xhci: do not perform Soft Retry for some xHCI hostsStanislaw Gruszka
On some systems rt2800usb and mt7601u devices are unable to operate since commit f8f80be501aa ("xhci: Use soft retry to recover faster from transaction errors") Seems that some xHCI controllers can not perform Soft Retry correctly, affecting those devices. To avoid the problem add xhci->quirks flag that restore pre soft retry xhci behaviour for affected xHCI controllers. Currently those are AMD_PROMONTORYA_4 and AMD_PROMONTORYA_2, since it was confirmed by the users: on those xHCI hosts issue happen and is gone after disabling Soft Retry. [minor commit message rewording for checkpatch -Mathias] Fixes: f8f80be501aa ("xhci: Use soft retry to recover faster from transaction errors") Cc: <stable@vger.kernel.org> # 4.20+ Reported-by: Bernhard <bernhard.gebetsberger@gmx.at> Tested-by: Bernhard <bernhard.gebetsberger@gmx.at> Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202541 Link: https://lore.kernel.org/r/20210311115353.2137560-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10usb: xhci-mtk: support to build xhci-mtk-hcd.koChunfeng Yun
Currently xhci-hcd.ko building depends on USB_XHCI_MTK, this is not flexible for some cases. For example: USB_XHCI_HCD is y, and USB_XHCI_MTK is m, then we can't implement extended functions if only update xhci-mtk.ko This patch is used to remove the dependence. Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/0b62e21ddfacc1c2874726dd27ccab80c993f303.1615170625.git.chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-08Merge 5.11-rc7 into usb-nextGreg Kroah-Hartman
We need the USB fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-02-03xhci: fix bounce buffer usage for non-sg list caseMathias Nyman
xhci driver may in some special cases need to copy small amounts of payload data to a bounce buffer in order to meet the boundary and alignment restrictions set by the xHCI specification. In the majority of these cases the data is in a sg list, and driver incorrectly assumed data is always in urb->sg when using the bounce buffer. If data instead is contiguous, and in urb->transfer_buffer, we may still need to bounce buffer a small part if data starts very close (less than packet size) to a 64k boundary. Check if sg list is used before copying data to/from it. Fixes: f9c589e142d0 ("xhci: TD-fragment, align the unsplittable case with a bounce buffer") Cc: stable@vger.kernel.org Reported-by: Andreas Hartmann <andihartmann@01019freenet.de> Tested-by: Andreas Hartmann <andihartmann@01019freenet.de> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210203113702.436762-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: handle halting transfer event properly after endpoint stop and halt raced.Mathias Nyman
If we receive a transfer event indicating that an endpoint should be halted, but current endpoint state doesn't match it, then the halt might be just resolved by the stop endpoint completion handler that detects the halted endpoint due to a context state error. In this case the TD we halted on is already moved to the cancelled TD list, and should not be successfully completed and given back anymore. Let the stop endpoint completion handler reset the endpoint, and then let the reset endpoint handler give back the cancelled TD among all other ones on the cancelled TD list Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-28-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: Check for pending reset endpoint command before queueing a new one.Mathias Nyman
A halted endpoint can be detected both when transfer events complete, and in stop endpoint command completion. Both these handlers will start clearing up the halted endpoint and queue a reset endpoint command. It's possible to get both events for the same halted endpoint if right after a URB cancel queues a stop endpoint command the endpoint stalls. Use the EP_HALTED flag to prevent resetting the endpoint twice. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-27-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: remove obsolete dequeue pointer moving codeMathias Nyman
xhci_find_new_dequeue_state() and xhci_queue_new_dequeue_state() are no longer used afer introducing the move_dequeue_past_td() function. also remove struct xhci_dequeue_state as its no longer used. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-26-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: introduce a new move_dequeue_past_td() function to replace old code.Mathias Nyman
Replace xhci_find_new_dequeue_state() and xhci_queue_new_dequeue_state() functions with one combined function. These function were always called after each other, and had a lot of extra code just to pass the newly found dequeue state from the first function to the other. The new function also returns error in case there is a failure to queue the new dequeue state. This way the caller can decide on recovery measures to handle it. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-25-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: handle stop endpoint command completion with endpoint in running state.Mathias Nyman
Handle race where a stop endpoint command fails with "context state error" as hardware hasn't actually started the ring yet after a previous urb cancellation completed and restarted the endpoint. Flushing the doorbell write that restart the endpoint reduced these cases, but didn't completely resolve them. Check if the ring is running in the stop endpoint completion handler, and issue a new stop endpoint command in this case. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-24-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: Fix halted endpoint at stop endpoint command completionMathias Nyman
xhci 4.6.9: "A busy endpoint may asynchronously transition from the Running to the Halted or Error state due to error conditions detected while processing TRBs. A possible race condition may occur if software, thinking an endpoint is in the running state, issues a Stop Endpoint Command, however at the same time the xHC asynchronously transitions the endpoint to the Halted or Error state. In this case, a Context State Error may be generated for the command completion. Software may verify that this case occurred by inspecting the EP State for Halted or Error when a Stop Endpoint Command results in a Context State Error." Halted endpoints were not detected or handled at all in the stop endpoint completion handler. A set TR Deq ptr command was bluntly queued instead of resetting the endpoint first. The set TR Deq command would fail with a context state error. Fix this case by resetting the halted endpoint first to get it to a stopped state instead of the halted (error) state. Handle cancelled TDs once endpoint reset completes, invalidating cancelled TDs on ring either by turning them to no-op, or in case ring stopped on cancelled TD then move hardware dequeue pointer past it, which will clear the cancelled TD from hw cache, and make sure HW does not process it Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-23-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: split handling halted endpoints into two stepsMathias Nyman
Don't queue both a reset endpoint command and a set TR deq command at once when handling a halted endpoint. split this into two steps. Initially only queue a reset endpoint command, and then if needed queue a set TR deq command in the reset endpoint handler. Note: This removes the RESET_EP_QUIRK handling which was added in commit ac9d8fe7c6a8 ("USB: xhci: Add quirk for Fresco Logic xHCI hardware.") This quirk was added in 2009 for prototype xHCI hardware meant for evaluation purposes only, and should not reach consumers. This hardware could not handle two commands queued at once, and had bad data in the output context after a reset endpoint command. After this patch two command are no longer queued at once, so that part is solved in this rewrite, but the workaround for bad data in the output context solved by issuing an extra configure endpoint command is bluntly removed. Adding this workaround to the new rewrite just adds complexity, and I think it's time to let this quirk go. Print a debug message instead. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-22-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: move and rename xhci_cleanup_halted_endpoint()Mathias Nyman
Halted endpoints can be discoverd both when handling transfer events and command completion events. Move code that handles halted endpoints before both of those event handlers. Rename the function to xhci_handle_halted_ep() to better describe what it does. Try to reserve "cleanup" word in function names for last stage cleanup activities. No functional changes Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-21-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: turn cancelled td cleanup to its own functionMathias Nyman
Refactor handler for stop endpoint command completion. Yank out the part that invalidates cancelled TDs and turn it into a separate function. Invalidating cancelled TDs should be done while the ring is stopped, but not exclusively in the stop endpoint command completeion handler. We will need to invalidate TDs after resetting endpoints as well. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-20-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: store TD status in the td struct instead of passing it alongMathias Nyman
In cases where the TD can't be given back in current handler we want to be able to store it until its time to return the TD. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-19-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: use xhci_td_cleanup() helper when giving back cancelled URBsMathias Nyman
use the existing xhci_td_cleanup() to give back cancelled TDs when a ring is stopped. A minor change to make sure we don't try to remove an already removed td from the list is needed as cancelled TDs are already removed from the td_list immediatelty when it's cancelled. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-18-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: move xhci_td_cleanup so it can be called by more functionsMathias Nyman
No funtional changes Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-17-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: Add xhci_reset_halted_ep() helper functionMathias Nyman
Create a separate helper function to issue reset endpont commands to clear halted endpoints. This is useful for cases where a halted endpoint is discovered while completing another command, and the endpoint halt needs to be cleared with a endpoint reset first. No functional changes Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-16-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: flush endpoint start to reduce race risk with stop endpoint command.Mathias Nyman
Stop endpoint command fails with "context state error" if the endpoint is already stopped. This case was observed when a previous URB cancel had just completed and rang the doorbell to restart the ring, when a new URB cancel queued a stop endpoint command. >From xHC hardware pov the endpoint had not yet started, so the stop endpoint command failed with context state error. Right after this the doorbell ring took effect and ring was restarted. Interrupt handler saw a stop endpoint command completion event with "context state error" and discovered that the ring was back up in running state. flushing the write reduces these cases in stress testing, but does not completely remove the issue. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-15-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: Check link TRBs when updating ring enqueue and dequeue pointers.Mathias Nyman
xhci driver relies on link TRBs existing in the correct places in TRB ring buffers shared with the host controller. The controller should not modify these link TRBs, but in theory a faulty xHC could do it. Add some basic sanity checks to avoid infinite loops in interrupt handler, or accessing unallocated memory outside a ring segment due to missing or misplaced link TRBs. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-14-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: avoid DMA double fetch when reading event trb type.Mathias Nyman
Instead of re-reading, masking and endianness correcting the same trb several times to get the trb type from an event, just do it once and store it in a local variable. Also pass the trb_type directly to the vendor specific event handler, avoiding one more similar read. In addition to the security benefit this also cleans up the code and helps readability. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-13-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: remove extra loop in interrupt contextMathias Nyman
When finishing a TD we walk the endpoint dequeue trb pointer until it matches the last TRB of the TD. TDs can contain over 100 TRBs, meaning we call a function 100 times, do a few comparisons and increase a couple values for each of these calls, all in interrupt context. This can all be avoided by adding a pointer to the last TRB segment, and a number of TRBs in the TD. So instead of walking through each TRB just set the new dequeue segment, pointer, and number of free TRBs directly. Getting rid of the while loop also reduces the risk of getting stuck in a infinite loop in the interrupt handler. Loop relied on valid matching dequeue and last_trb values to break. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-12-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: check slot_id is valid before gathering slot infoLalithambika Krishna Kumar
Check that the slot_id that we dug out from command completion event TRB, is valid before using it to identify the slot associated with the command that generated the event. Signed-off-by: Lalithambika Krishna Kumar <lalithambika.krishnakumar@intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-11-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: prevent a theoretical endless loop while preparing rings.Mathias Nyman
xhci driver links together segments in a ring buffer by turning the last TRB of a segment into a link TRB, pointing to the beginning of the next segment. If the first TRB of every segment for some unknown reason is a link TRB pointing to the next segment, then prepare_ring() loops indefinitely. This isn't something the xhci driver would do. xHC hardware has access to these rings, it sholdn't be writing link TRBs either, but with broken xHC hardware this could in theory be possible. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-10-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: remove xhci_stream_id_to_ring() helperMathias Nyman
The one case that used this function can use the xhci_triad_to_transfer_ring() helper instead. Avoid having several functions doing basically the same thing. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-9-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: add xhci_virt_ep_to_ring() helperMathias Nyman
Two existing ring helpers, xhci_triad_to_transfer_ring() and xhci_stream_id_to_ring() have partially similar functionality. Both have some limitation, especieally with boundary checking. Add a new xhci_virt_ep_to_ring() helper with proper boundary checking that can replace parts of one helper, and later will completely replace the other helper. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-8-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: check virt_dev is valid before dereferencing itMathias Nyman
Check that the xhci_virt_dev structure that we dug out based on a slot_id value from a command completion is valid before dereferencing it. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-7-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: add xhci_get_virt_ep() helperMathias Nyman
In several event handlers we need to find the right endpoint structure from slot_id and ep_index in the event. Add a helper for this, check that slot_id and ep_index are valid. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-6-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: remove unused event parameter from completion handlersMathias Nyman
several command completion handlers are passed the event trb as a paramtere even if it't not used. Remove it. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-5-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: adjust parameters passed to cleanup_halted_endpoint()Mathias Nyman
Instead of passing slot id and endpoint index to cleanup_halted_endpoint() pass the endpoint structure pointer as it's already known. Avoids again digging out the endpoint structure based on slot id and endpoint index, and passing them along the call chain for this purpose only. Add slot_id to the virt_dev structure so that it can easily be found from a virt_dev, or its child, the virt_ep endpoint structure. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: get isochronous ring directly from endpoint structureMathias Nyman
isochronous endpoints do not support streams, meaning that there is only one ring per endpoint. Avoid double-fetching the transfer event DMA to get the ring. Also makes passing the event to skip_isoc_td() uncecessary. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-29xhci: Avoid parsing transfer events several timesMathias Nyman
When handling transfer events the event is passed along the handling callpath and parsed again in several occasions. The event contains slot_id and endpoint index, from which the driver endpoint structure can be found. There wasn't however a way to get the endpoint index or parent usb device from this endpoint structure. A lot of extra event parsing, and thus some DMA doublefetch cases, and excess variables and code can be avoided by adding endpoint index and parent usb virt device pointer to the endpoint structure. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210129130044.206855-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-15xhci: make sure TRB is fully written before giving it to the controllerMathias Nyman
Once the command ring doorbell is rung the xHC controller will parse all command TRBs on the command ring that have the cycle bit set properly. If the driver just started writing the next command TRB to the ring when hardware finished the previous TRB, then HW might fetch an incomplete TRB as long as its cycle bit set correctly. A command TRB is 16 bytes (128 bits) long. Driver writes the command TRB in four 32 bit chunks, with the chunk containing the cycle bit last. This does however not guarantee that chunks actually get written in that order. This was detected in stress testing when canceling URBs with several connected USB devices. Two consecutive "Set TR Dequeue pointer" commands got queued right after each other, and the second one was only partially written when the controller parsed it, causing the dequeue pointer to be set to bogus values. This was seen as error messages: "Mismatch between completed Set TR Deq Ptr command & xHCI internal state" Solution is to add a write memory barrier before writing the cycle bit. Cc: <stable@vger.kernel.org> Tested-by: Ross Zwisler <zwisler@google.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20210115161907.2875631-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-09usb: xhci: Use temporary buffer to consolidate SGTejas Joglekar
The Synopsys xHC has an internal TRB cache of size TRB_CACHE_SIZE for each endpoint. The default value for TRB_CACHE_SIZE is 16 for SS and 8 for HS. The controller loads and updates the TRB cache from the transfer ring in system memory whenever the driver issues a start transfer or update transfer command. For chained TRBs, the Synopsys xHC requires that the total amount of bytes for all TRBs loaded in the TRB cache be greater than or equal to 1 MPS. Or the chain ends within the TRB cache (with a last TRB). If this requirement is not met, the controller will not be able to send or receive a packet and it will hang causing a driver timeout and error. This can be a problem if a class driver queues SG requests with many small-buffer entries. The XHCI driver will create a chained TRB for each entry which may trigger this issue. This patch adds logic to the XHCI driver to detect and prevent this from happening. For every (TRB_CACHE_SIZE - 2), we check the total buffer size of the SG list and if the last window of (TRB_CACHE_SIZE - 2) SG list length and we don't make up at least 1 MPS, we create a temporary buffer to consolidate full SG list into the buffer. We check at (TRB_CACHE_SIZE - 2) window because it is possible that there would be a link and/or event data TRB that take up to 2 of the cache entries. We discovered this issue with devices on other platforms but have not yet come across any device that triggers this on Linux. But it could be a real problem now or in the future. All it takes is N number of small chained TRBs. And other instances of the Synopsys IP may have smaller values for the TRB_CACHE_SIZE which would exacerbate the problem. Signed-off-by: Tejas Joglekar <joglekar@synopsys.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20201208092912.1773650-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-13usb: fix a few cases of -WfallthroughNick Desaulniers
The "fallthrough" pseudo-keyword was added as a portable way to denote intentional fallthrough. Clang will still warn on cases where there is a fallthrough to an immediate break. Add explicit breaks for those cases. Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Link: https://lore.kernel.org/r/20201111014716.260633-1-ndesaulniers@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-09-20xhci: Tune interrupt blocking for isochronous transfersMathias Nyman
controllers with XHCI_AVOID_BEI quirk cause too frequent interrupts and affect power management. To avoid interrupting on every isochronous interval the BEI (Block Event Interrupt) flag is set for all except the last Isoch TRB in a URB. This lead to event ring filling up in case several isoc URB were queued and cancelled rapidly, which some controllers didn't handle well, and thus the XHCI_AVOID_BEI quirk was introduced. see commit 227a4fd801c8 ("usb: xhci: apply XHCI_AVOID_BEI quirk to all Intel xHCI controllers") With the XHCI_AVOID_BEI quirk each Isoch TRB will trigger an interrupt. This can cause up to 8000 interrupts per second for isochronous transfers with HD USB3 cameras, affecting power saving. The event ring fits 256 events, instead of interrupting on every isochronous TRB if XHCI_AVOID_BEI is set we make sure at least every 8th Isochronous TRB asserts an interrupt, clearing the event ring. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200918131752.16488-9-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-05-14usb: xhci: Fix NULL pointer dereference when enqueuing trbs from urb sg listSriharsha Allenki
On platforms with IOMMU enabled, multiple SGs can be coalesced into one by the IOMMU driver. In that case the SG list processing as part of the completion of a urb on a bulk endpoint can result into a NULL pointer dereference with the below stack dump. <6> Unable to handle kernel NULL pointer dereference at virtual address 0000000c <6> pgd = c0004000 <6> [0000000c] *pgd=00000000 <6> Internal error: Oops: 5 [#1] PREEMPT SMP ARM <2> PC is at xhci_queue_bulk_tx+0x454/0x80c <2> LR is at xhci_queue_bulk_tx+0x44c/0x80c <2> pc : [<c08907c4>] lr : [<c08907bc>] psr: 000000d3 <2> sp : ca337c80 ip : 00000000 fp : ffffffff <2> r10: 00000000 r9 : 50037000 r8 : 00004000 <2> r7 : 00000000 r6 : 00004000 r5 : 00000000 r4 : 00000000 <2> r3 : 00000000 r2 : 00000082 r1 : c2c1a200 r0 : 00000000 <2> Flags: nzcv IRQs off FIQs off Mode SVC_32 ISA ARM Segment none <2> Control: 10c0383d Table: b412c06a DAC: 00000051 <6> Process usb-storage (pid: 5961, stack limit = 0xca336210) <snip> <2> [<c08907c4>] (xhci_queue_bulk_tx) <2> [<c0881b3c>] (xhci_urb_enqueue) <2> [<c0831068>] (usb_hcd_submit_urb) <2> [<c08350b4>] (usb_sg_wait) <2> [<c089f384>] (usb_stor_bulk_transfer_sglist) <2> [<c089f2c0>] (usb_stor_bulk_srb) <2> [<c089fe38>] (usb_stor_Bulk_transport) <2> [<c089f468>] (usb_stor_invoke_transport) <2> [<c08a11b4>] (usb_stor_control_thread) <2> [<c014a534>] (kthread) The above NULL pointer dereference is the result of block_len and the sent_len set to zero after the first SG of the list when IOMMU driver is enabled. Because of this the loop of processing the SGs has run more than num_sgs which resulted in a sg_next on the last SG of the list which has SG_END set. Fix this by check for the sg before any attributes of the sg are accessed. [modified reason for null pointer dereference in commit message subject -Mathias] Fixes: f9c589e142d04 ("xhci: TD-fragment, align the unsplittable case with a bounce buffer") Cc: stable@vger.kernel.org Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200514110432.25564-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-21xhci: Don't clear hub TT buffer on ep0 protocol stallMathias Nyman
The default control endpoint ep0 can return a STALL indicating the device does not support the control transfer requests. This is called a protocol stall and does not halt the endpoint. xHC behaves a bit different. Its internal endpoint state will always be halted on any stall, even if the device side of the endpiont is not halted. So we do need to issue the reset endpoint command to clear the xHC host intenal endpoint halt state, but should not request the HS hub to clear the TT buffer unless device side of endpoint is halted. Clearing the hub TT buffer at protocol stall caused ep0 to become unresponsive for some FS/LS devices behind HS hubs, and class drivers failed to set the interface due to timeout: usb 1-2.1: 1:1: usb_set_interface failed (-110) Fixes: ef513be0a905 ("usb: xhci: Add Clear_TT_Buffer") Cc: <stable@vger.kernel.org> # v5.3 Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200421140822.28233-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-21xhci: Fix handling halted endpoint even if endpoint ring appears emptyMathias Nyman
If a class driver cancels its only URB then the endpoint ring buffer will appear empty to the xhci driver. xHC hardware may still process cached TRBs, and complete with a STALL, halting the endpoint. This halted endpoint was not handled correctly by xhci driver as events on empty rings were all assumed to be spurious events. xhci driver refused to restart the ring with EP_HALTED flag set, so class driver was never informed the endpoint halted even if it queued new URBs. The host side of the endpoint needs to be reset, and dequeue pointer should be moved in order to clear the cached TRBs and resetart the endpoint. Small adjustments in finding the new dequeue pointer are needed to support the case of stall on an empty ring and unknown current TD. Cc: <stable@vger.kernel.org> cc: Jeremy Compostella <jeremy.compostella@intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200421140822.28233-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12xhci: Wait until link state trainsits to U0 after setting USB_SS_PORT_LS_U0Kai-Heng Feng
Like U3 case, xHCI spec doesn't specify the upper bound of U0 transition time. The 20ms is not enough for some devices. Intead of polling PLS or PLC, we can facilitate the port change event to know that the link transits to U0 is completed. While at it, also separate U0 and U3 case to make the code cleaner. [variable rename to u3exit, and skip completion for usb2 ports -Mathias ] Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200312144517.1593-8-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12xhci: Show host status when watchdog triggers and host is assumed dead.Mathias Nyman
Additional debugging to show xHC USBSTS register when stop endpoint command watchdog triggers and host is assumed dead. useful to know the current status before the controller is stopped by the xhci driver and everything is released and freed. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200312144517.1593-4-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-12xhci: Add a separate debug message for split transaction errors.Mathias Nyman
Don't show the same error message for transaction errors and split transaction errors. It's very confusing while debugging. Transaction errors are often due to electrical interference. Split transaction errors are about xHC not being able to schedule start and complete split transactions needed to address low- and full-speed devices behind high-speed hubs. Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20200312144517.1593-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-11xhci: handle some XHCI_TRUST_TX_LENGTH quirks cases as default behaviour.Mathias Nyman
xhci driver claims it needs XHCI_TRUST_TX_LENGTH quirk for both Broadcom/Cavium and a Renesas xHC controllers. The quirk was inteded for handling false "success" complete event for transfers that had data left untransferred. These transfers should complete with "short packet" events instead. In these two new cases the false "success" completion is reported after a "short packet" if the TD consists of several TRBs. xHCI specs 4.10.1.1.2 say remaining TRBs should report "short packet" as well after the first short packet in a TD, but this issue seems so common it doesn't make sense to add the quirk for all vendors. Turn these events into short packets automatically instead. This gets rid of the "The WARN Successful completion on short TX for slot 1 ep 1: needs XHCI_TRUST_TX_LENGTH quirk" warning in many cases. Cc: <stable@vger.kernel.org> Reported-by: Eli Billauer <eli.billauer@gmail.com> Reported-by: Ard Biesheuvel <ardb@kernel.org> Tested-by: Eli Billauer <eli.billauer@gmail.com> Tested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20191211142007.8847-6-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-11xhci: fix USB3 device initiated resume race with roothub autosuspendMathias Nyman
A race in xhci USB3 remote wake handling may force device back to suspend after it initiated resume siganaling, causing a missed resume event or warm reset of device. When a USB3 link completes resume signaling and goes to enabled (UO) state a interrupt is issued and the interrupt handler will clear the bus_state->port_remote_wakeup resume flag, allowing bus suspend. If the USB3 roothub thread just finished reading port status before the interrupt, finding ports still in suspended (U3) state, but hasn't yet started suspending the hub, then the xhci interrupt handler will clear the flag that prevented roothub suspend and allow bus to suspend, forcing all port links back to suspended (U3) state. Example case: usb_runtime_suspend() # because all ports still show suspended U3 usb_suspend_both() hub_suspend(); # successful as hub->wakeup_bits not set yet ==> INTERRUPT xhci_irq() handle_port_status() clear bus_state->port_remote_wakeup usb_wakeup_notification() sets hub->wakeup_bits; kick_hub_wq() <== END INTERRUPT hcd_bus_suspend() xhci_bus_suspend() # success as port_remote_wakeup bits cleared Fix this by increasing roothub usage count during port resume to prevent roothub autosuspend, and by making sure bus_state->port_remote_wakeup flag is only cleared after resume completion is visible, i.e. after xhci roothub returned U0 or other non-U3 link state link on a get port status request. Issue rootcaused by Chiasheng Lee Cc: <stable@vger.kernel.org> Cc: Lee, Hou-hsun <hou-hsun.lee@intel.com> Reported-by: Lee, Chiasheng <chiasheng.lee@intel.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20191211142007.8847-3-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-16usb: host: xhci: Support running urb giveback in tasklet contextSuwan Kim
Patch "USB: HCD: support giveback of URB in tasklet context"[1] introduced giveback of urb in tasklet context. [1] This patch was applied to ehci but not xhci. [2] This patch significantly reduces the hard irq time of xhci. Especially for uvc driver, the hard irq including the uvc completion function runs quite long but applying this patch reduces the hard irq time of xhci. I have tested four SS devices to check if performance degradation occurs when urb completion functions run in the tasklet context. As a result of the test, all devices works well and shows very similar performance with the upstream kernel. Moreover, usb ethernet adapter show better performance than the upstream kernel about 5% for RX and 2% for TX. Four SS devices is as follows. SS devices for test 1. WD My Passport 2TB (external hard drive) 2. Sandisk Ultra Flair USB 3.0 32GB 3. Logitech Brio webcam 4. Iptime 1gigabit ethernet adapter (Mediatek RTL8153) Test description 1. Mass storage (hard drive) performance test - run below command 10 times and compute the average performance dd if=/dev/sdN iflag=direct of=/dev/null bs=1G count=1 2. Mass storage (flash memory) performance test - run below command 10 times and compute the average performance dd if=/dev/sdN iflag=direct of=/dev/null bs=1G count=1 3. Webcam streaming performance test - run simple capture program and get the average frame rate per second - capture 1500 frames - program link https://github.com/asfaca/Webcam-performance-analyzing-tool - video resolution : 4096 X 2160 (4K) at 30 or 24 fps - device (Logitech Brio) spec url for the highest resolution and fps https://support.logitech.com/en_gb/product/brio-stream/specs 4. USB Ethernet adapter performance test - directly connect two linux machines with ethernet cable - run pktgen of linux kernel and send 1500 bytes packets - run vnstat to measure the network bandwidth for 180 seconds Test machine - CPU : Intel i5-7600 @ 3.5GHz Test results 1. Mass storage (hard drive) performance test WD My Passport 2TB (external hard drive) -------------------------------------------------------------------- xhci without tasklet | xhci with tasklet -------------------------------------------------------------------- 103.667MB/s | 103.692MB/s -------------------------------------------------------------------- 2. Mass storage (flash memory) performance test Sandisk Ultra Flair USB 3.0 32GB -------------------------------------------------------------------- xhci without tasklet | xhci with tasklet -------------------------------------------------------------------- 129.727MB/s | 130.2MB/s -------------------------------------------------------------------- 3. Webcam streaming performance test Logitech Brio webcam -------------------------------------------------------------------- xhci without tasklet | xhci with tasklet -------------------------------------------------------------------- 26.4451 fps | 26.3949 fps -------------------------------------------------------------------- 4. USB Ethernet adapter performance test Iptime 1gigabit ethernet adapter (Mediatek RTL8153) -------------------------------------------------------------------- xhci without tasklet | xhci with tasklet -------------------------------------------------------------------- RX 933.86 Mbit/s | 983.86 Mbit/s -------------------------------------------------------------------- TX 830.18 Mbit/s | 882.75 Mbit/s -------------------------------------------------------------------- [1], https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=94dfd7edfd5c9b605caf7b562de7a813d216e011 [2], https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=428aac8a81058e2303677a8fbf26670229e51d3a Signed-off-by: Suwan Kim <suwan.kim027@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/1573836603-10871-4-git-send-email-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-16xhci: Add tracing for xhci doorbell register writesMathias Nyman
Trace when a register in the doorbell array is written, both for host controller command doorbell and device doorbells, including for which endpoint and stream Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/1573836603-10871-3-git-send-email-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>