litmus-rt.git/drivers/usb/host, branch test

usb: host: xhci: add mutex for non-thread-safe data

2015-05-24T16:23:28+00:00

Regression in commit 638139eb95d2 ("usb: hub: allow to process more usb
hub events in parallel")

The regression resulted in intermittent failure to initialise a 10-port
hub (with three internal VL812 4-port hub controllers) on boot, with a
failure rate of around 8%, due to multiple race conditions when
accessing addr_dev and slot_id in struct xhci_hcd.

This regression also exposed a problem with xhci_setup_device, which
"should be protected by the usb_address0_mutex" but no longer is due to

commit 6fecd4f2a58c ("USB: separate usb_address0 mutexes for each bus")

With separate buses (and locks) it is no longer the case that a single
lock will protect xhci_setup_device from accesses by two parallel
threads processing events on the two buses.

Fix this by adding a mutex to protect addr_dev and slot_id in struct
xhci_hcd, and by making the assignment of slot_id atomic.

Fixes multiple boot errors:

[ 0.583008] xhci_hcd 0000:00:14.0: Bad Slot ID 2
[ 0.583009] xhci_hcd 0000:00:14.0: Could not allocate xHCI USB device data structures
[ 0.583012] usb usb1-port3: couldn't allocate usb_device

And:

[ 0.637409] xhci_hcd 0000:00:14.0: Error while assigning device slot ID
[ 0.637417] xhci_hcd 0000:00:14.0: Max number of devices this xHCI host supports is 32.
[ 0.637421] usb usb1-port1: couldn't allocate usb_device

And:

[ 0.753372] xhci_hcd 0000:00:14.0: ERROR: unexpected setup context command completion code 0x0.
[ 0.753373] usb 1-3: hub failed to enable device, error -22
[ 0.753400] xhci_hcd 0000:00:14.0: Error while assigning device slot ID
[ 0.753402] xhci_hcd 0000:00:14.0: Max number of devices this xHCI host supports is 32.
[ 0.753403] usb usb1-port3: couldn't allocate usb_device

And:

[ 11.018386] usb 1-3: device descriptor read/all, error -110

And:

[ 5.753838] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command

Tested with 200 reboots, resulting in no USB hub init related errors.

Fixes: 638139eb95d2 ("usb: hub: allow to process more usb hub events in parallel")
Link: https://lkml.kernel.org/g/CAP-bSRb=A0iEYobdGCLpwynS7pkxpt_9ZnwyZTPVAoy0Y=Zo3Q@mail.gmail.com
Signed-off-by: Chris Bainbridge 
Cc:  # 3.18+
[changed git commit description style for checkpatch -Mathias]
Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

usb: make module xhci_hcd removable

2015-05-24T16:23:28+00:00

Fixed regression. After commit 29e409f0f761 ("xhci: Allow xHCI drivers to
be built as separate modules") the module xhci_hcd became non-removable.
That behaviour is not expected and there're no notes about it in commit
message. The module should be removable as it blocks PM suspend/resume
functions (Debian Bug#666406).

Signed-off-by: Arthur Demchenkov 
Reviewed-by: Andrew Bresticker 
Cc:  # v3.18+
Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

xhci: gracefully handle xhci_irq dead device

2015-05-09T16:27:32+00:00

If the xHCI host controller has died (ie, device removed) or suffered
other serious fatal error (STS_FATAL), then xhci_irq should handle this
condition with IRQ_HANDLED instead of -ESHUTDOWN.

Signed-off-by: Joe Lawrence 
Cc: 
Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

xhci: Solve full event ring by increasing TRBS_PER_SEGMENT to 256

2015-05-09T16:27:32+00:00

Our event ring consists of only one segment, and we risk filling
the event ring in case we get isoc transfers with short intervals
such as webcams that fill a TD every microframe (125us)

With 64 TRB segment size one usb camera could fill the event ring in 8ms.
A setup with several cameras and other devices can fill up the
event ring as it is shared between all devices.
This has occurred when uvcvideo queues 5 * 32TD URBs which then
get cancelled when the video mode changes. The cancelled URBs are returned
in the xhci interrupt context and blocks the interrupt handler from
handling the new events.

A full event ring will block xhci from scheduling traffic and affect all
devices conneted to the xhci, will see errors such as Missed Service
Intervals for isoc devices, and  and Split transaction errors for LS/FS
interrupt devices.

Increasing the TRB_PER_SEGMENT will also increase the default endpoint ring
size, which is welcome as for most isoc transfer we had to dynamically
expand the endpoint ring anyway to be able to queue the 5 * 32TDs uvcvideo
queues.

The default size used to be 64 TRBs per segment

Cc: 
Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

xhci: fix isoc endpoint dequeue from advancing too far on transaction error

2015-05-09T16:27:32+00:00

Isoc TDs usually consist of one TRB, sometimes two. When all goes well we
receive only one success event for a TD, and move the dequeue pointer to
the next TD.

This fails if the TD consists of two TRBs and we get a transfer error
on the first TRB, we will then see two events for that TD.

Fix this by making sure the event we get is for the last TRB in that TD
before moving the dequeue pointer to the next TD. This will resolve some
of the uvc and dvb issues with the
"ERROR Transfer event TRB DMA ptr not part of current TD" error message

Cc: 
Signed-off-by: Mathias Nyman 
Signed-off-by: Greg Kroah-Hartman

Revert "usb: host: ehci-msm: Use devm_ioremap_resource instead of devm_ioremap"

2015-04-28T10:51:30+00:00

This reverts commit 70843f623b58 ("usb: host: ehci-msm: Use
devm_ioremap_resource instead of devm_ioremap") and commit
e507bf577e5a ("host: ehci-msm: remove duplicate check on resource"),
because msm_otg and this driver are using same address space to
access AHB mode and USB command registers.

Signed-off-by: Ivan T. Ivanov 
Acked-by: Alan Stern 
Acked-by: Vivek Gautam 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2015-04-14T17:49:03+00:00

Pull tracing updates from Steven Rostedt:
 "Some clean ups and small fixes, but the biggest change is the addition
  of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.

  Tracepoints have helper functions for the TP_printk() called
  __print_symbolic() and __print_flags() that lets a numeric number be
  displayed as a a human comprehensible text.  What is placed in the
  TP_printk() is also shown in the tracepoint format file such that user
  space tools like perf and trace-cmd can parse the binary data and
  express the values too.  Unfortunately, the way the TRACE_EVENT()
  macro works, anything placed in the TP_printk() will be shown pretty
  much exactly as is.  The problem arises when enums are used.  That's
  because unlike macros, enums will not be changed into their values by
  the C pre-processor.  Thus, the enum string is exported to the format
  file, and this makes it useless for user space tools.

  The TRACE_DEFINE_ENUM() solves this by converting the enum strings in
  the TP_printk() format into their number, and that is what is shown to
  user space.  For example, the tracepoint tlb_flush currently has this
  in its format file:

     __print_symbolic(REC->reason,
        { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
        { TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
        { TLB_LOCAL_SHOOTDOWN, "local shootdown" },
        { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })

  After adding:

     TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
     TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);

  Its format file will contain this:

     __print_symbolic(REC->reason,
        { 0, "flush on task switch" },
        { 1, "remote shootdown" },
        { 2, "local shootdown" },
        { 3, "local mm shootdown" })"

* tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
  tracing: Add enum_map file to show enums that have been mapped
  writeback: Export enums used by tracepoint to user space
  v4l: Export enums used by tracepoints to user space
  SUNRPC: Export enums in tracepoints to user space
  mm: tracing: Export enums in tracepoints to user space
  irq/tracing: Export enums in tracepoints to user space
  f2fs: Export the enums in the tracepoints to userspace
  net/9p/tracing: Export enums in tracepoints to userspace
  x86/tlb/trace: Export enums in used by tlb_flush tracepoint
  tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()
  tracing: Allow for modules to convert their enums to values
  tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values
  tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation
  tracing: Give system name a pointer
  brcmsmac: Move each system tracepoints to their own header
  iwlwifi: Move each system tracepoints to their own header
  mac80211: Move message tracepoints to their own header
  tracing: Add TRACE_SYSTEM_VAR to xhci-hcd
  tracing: Add TRACE_SYSTEM_VAR to kvm-s390
  tracing: Add TRACE_SYSTEM_VAR to intel-sst
  ...

Merge tag 'usb-for-v4.1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-testing

2015-04-10T11:45:27+00:00

Felipe writes:

usb: generic resume timeout for v4.1

This part 2 pull request contains only the patches
which make sure everybody on linux uses the same
resume timeout value.

Signed-off-by: Felipe Balbi

usb: host: sl811: use new USB_RESUME_TIMEOUT

2015-04-07T17:58:36+00:00

Make sure we're using the new macro, so our
resume signaling will always pass certification.

Cc:  # v3.10+
Signed-off-by: Felipe Balbi

usb: host: r8a66597: use new USB_RESUME_TIMEOUT

2015-04-07T17:58:35+00:00

While this driver was already using a 50ms resume
timeout, let's make sure everybody uses the same
macro so it's easy to fix later should anything
go wrong.

It also gives a more "stable" expectation to Linux
users.

Cc:  # v3.10+
Signed-off-by: Felipe Balbi