Commit graph

404 commits

Author SHA1 Message Date
Mathias Nyman 5eee4b6b4f xhci: support calling cleanup_halted_endpoint with soft retry
Add soft reset support to cleanup_halted_endpoint().
using soft reset will prevent it from setting a new dequeue pointer to
start the transfer from. Let it continue where it halted.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-15 22:17:46 +02:00
Mathias Nyman 217491487c xhci: Add support for endpoint soft reset
xhci supports soft retry recovery when the host halted the host side of an
endopint but the connected USB device is not aware of the halt.

In this case xhci needs to issue a reset endopint command  with a TSP
(Transfer State Preserve) flag set which preserves the Data toggle
and Sequence number of the endpoint.

This feature is needed to handle a few special transfer event types
such as USB Transaction error that don't always point to a causing TRB.

see xhci 4.6.8.1 for more details

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-15 22:17:46 +02:00
Mathias Nyman b3368382ef xhci: refactor transfer event errors and completion codes
Parse the transfer event first, and remove duplicate debugging
code.

Reorder completion codes according to endpoint state.

No functional changes

We are not handling some transfer events correcly and need to
clean up this before fixing it

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-15 22:17:46 +02:00
Mathias Nyman e6b20121c6 xhci: Add helper to get hardware dequeue pointer for stopped rings.
Add xhci_get_hw_deq() helper to retrieve the hardware dequeue pointer an
endpoint or stream stopped on.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:02:58 +09:00
Mathias Nyman 8790736dbf xhci: Add stream id to xhci_dequeue_state structure
The values for the new dequeue segment, new dequeue pointer and new cycle
state are needed for manually moving the xHC ring dequeue pointer.
These are conveniently stored in a xhci_dequeue_state structure.

stream support was added later and stream_id was carried
as a function parameter.

Move the stream_id to the xhci_dequeue_state structure instead.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:02:58 +09:00
Mathias Nyman cdd504e113 xhci: Find out where an endpoint or stream stopped from its context.
When xHC is asked to stop an endpoint it will save the position it
stopped on in the endpoint or stream context.

xhci driver needs to know if the controller stopped on the exact same
TRB that the driver was asked to cancel as it then needs to move past
the TD instead of turning the TD to no-op TRBs.

xhci driver used to get the stopped position from a "stopped" transfer
event before the stop endpoint command completed, but if the ring
is already stopped, or in a halted or error state this event is missing.

Get the stopped position from the endpoint or stream context instead

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:02:58 +09:00
Mathias Nyman 11e1d25db6 xhci: remove unused stopped_td pointer
We no longer keep track of where we stopped in a stopped_td pointer.
We get the ring dequeue pointer from the endpoint or stream context

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:02:58 +09:00
Mathias Nyman 604d02a2a6 xhci: Fix command ring stop regression in 4.11
In 4.11 TRB completion codes were renamed to match spec.

Completion codes for command ring stopped and endpoint stopped
were mixed, leading to failures while handling a stopped command ring.

Use the correct completion code for command ring stopped events.

Fixes: 0b7c105a04 ("usb: host: xhci: rename completion codes to match spec")
Cc: <stable@vger.kernel.org> # 4.11
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 15:19:42 +02:00
Alan Stern 63aea0dbab USB: xhci: fix lock-inversion problem
With threaded interrupts, bottom-half handlers are called with
interrupts enabled.  Therefore they can't safely use spin_lock(); they
have to use spin_lock_irqsave().  Lockdep warns about a violation
occurring in xhci_irq():

=========================================================
[ INFO: possible irq lock inversion dependency detected ]
4.11.0-rc8-dbg+ #1 Not tainted
---------------------------------------------------------
swapper/7/0 just changed the state of lock:
 (&(&ehci->lock)->rlock){-.-...}, at: [<ffffffffa0130a69>]
ehci_hrtimer_func+0x29/0xc0 [ehci_hcd]
but this lock took another, HARDIRQ-unsafe lock in the past:
 (hcd_urb_list_lock){+.....}

and interrupts could create inverse lock ordering between them.

other info that might help us debug this:
 Possible interrupt unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(hcd_urb_list_lock);
                               local_irq_disable();
                               lock(&(&ehci->lock)->rlock);
                               lock(hcd_urb_list_lock);
  <Interrupt>
    lock(&(&ehci->lock)->rlock);
 *** DEADLOCK ***

no locks held by swapper/7/0.
the shortest dependencies between 2nd lock and 1st lock:
 -> (hcd_urb_list_lock){+.....} ops: 252 {
    HARDIRQ-ON-W at:
                      __lock_acquire+0x602/0x1280
                      lock_acquire+0xd5/0x1c0
                      _raw_spin_lock+0x2f/0x40
                      usb_hcd_unlink_urb_from_ep+0x1b/0x60 [usbcore]
                      xhci_giveback_urb_in_irq.isra.45+0x70/0x1b0 [xhci_hcd]
                      finish_td.constprop.60+0x1d8/0x2e0 [xhci_hcd]
                      xhci_irq+0xdd6/0x1fa0 [xhci_hcd]
                      usb_hcd_irq+0x26/0x40 [usbcore]
                      irq_forced_thread_fn+0x2f/0x70
                      irq_thread+0x149/0x1d0
                      kthread+0x113/0x150
                      ret_from_fork+0x2e/0x40

This patch fixes the problem.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 15:19:42 +02:00
Peter Chen 6a29beef9d usb: host: xhci-ring: don't need to clear interrupt pending for MSI enabled hcd
According to xHCI spec Figure 30: Interrupt Throttle Flow Diagram

	If PCI Message Signaled Interrupts (MSI or MSI-X) are enabled,
       	then the assertion of the Interrupt Pending (IP) flag in Figure 30
       	generates a PCI Dword write. The IP flag is automatically cleared
       	by the completion of the PCI write.

the MSI enabled HCs don't need to clear interrupt pending bit, but
hcd->irq = 0 doesn't equal to MSI enabled HCD. At some Dual-role
controller software designs, it sets hcd->irq as 0 to avoid HCD
requesting interrupt, and they want to decide when to call usb_hcd_irq
by software.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 15:19:41 +02:00
Mathias Nyman 7bc5d5aff3 usb: xhci: trace URB before giving it back instead of after
Don't access any members of a URB after giving it back.
URB might be freed by then already.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-18 15:19:41 +02:00
Lu Baolu 8c10152ec5 usb: xhci: remove xhci_debug_trb()
Every XHCI TRB has already been traced by the trb trace events.
It is unnecessary to put the same message in kernel log. This
patch removes xhci_debug_trb().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:42 +02:00
Lu Baolu 121dcf1190 usb: xhci: remove ring debugging code
XHCI ring changes have already been traced by the ring trace
events. It's unnecessary to put the same messages in kernel
log. This patch removes the debugging code for a ring.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:41 +02:00
Lu Baolu cd12fd9f6d usb: xhci: remove enq_updates and deq_updates from ring
enq_updates and deq_updates were introduced in the first place
to check whether an xhci hardware is able to respond to trbs
enqueued in the ring. We now have trb tracers to trace every
single enqueue/dequeue trb. It's time to remove them and the
associated debugging code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:41 +02:00
Lu Baolu 74e0b5649c usb: xhci: remove error messages for failed memory allocation
Omit extra messages for memory allocation failure.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:41 +02:00
Lu Baolu b2d6edbb95 usb: xhci: add xhci_log_ring trace events
This patch creates a new event class called xhci_log_ring, and
defines the events used for tracing the change of all kinds of
rings used by an xhci host. An xHCI ring is basically a memory
block shared between software and hardware. By tracing changes
of rings, it makes the life easier for debugging hardware or
software problems.

This info can be used, later, to print, in a human readable way,
the life cycle of an xHCI ring using the trace-cmd tool and the
appropriate plugin.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:41 +02:00
Mathias Nyman d9f11ba9f1 xhci: Rework how we handle unresponsive or hoptlug removed hosts
Introduce a new xhci_hc_died() function that takes care of handling
pending commands and URBs if a host controller becomes unresponsive.

This addresses issues on hotpluggable xhci controllers that disappear
from the bus suddenly, often while the bus (PCI) remove function is
still being processed.

xhci_hc_died() sets a XHCI_STATUS_DYING flag to prevent new URBs and
commands or to be queued. The flag also ensures xhci_hc_died() will
give back pending commands and URBs once.

Host is considered dead if register read returns 0xffffffff, or host
fails to abort the command ring, or fails stopping an endpoint after
trying for 5 seconds.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:41 +02:00
Zhengjun Xing b7f769ae1b xhci: add slot and endpoint numbers to debug messages in handle_tx_event
There's one annoyance in how xhci prints debug messages, we often
get logs with messages but it's hard to say from which device and
endpoint the message originates. Add slot_id, ep_index messages
in handle_tx_event.

Signed-off-by: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:41 +02:00
Felipe Balbi 19a7d0d65c usb: host: xhci: add Slot and EP Context tracers
With these, we can track what's happening with the HW while executing
each and every command. It will give us visibility into how the
different contexts are being modified by xHC which can bring insight
into problems while debugging.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 12:17:41 +02:00
Mathias Nyman 0ab2881a40 xhci: Set URB actual length for stopped control transfers
A control transfer that stopped at the status stage incorrectly
warned about a "unexpected TRB Type 4", and did not set the
transferred actual_length for the URB.

The URB actual_length for control transfers should contain the
bytes transferred in the data stage.

Bytes of a partially sent setup stage and missing bytes from
status stage should be left out.

Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-29 12:13:49 +02:00
Mathias Nyman 7e64b0373a xhci: simplify how we store TDs in urb private data
Instead of storing a zero length array of td pointers, and then
allocate memory both for the td pointer array and the td's, just
use a zero length array of actual td's in urb private data.

old:

struct urb_priv {
       struct xhci_td *td[0]
}

new:

struct urb_priv {
        struct xhci_td td[0]
}

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:00:02 +01:00
Mathias Nyman 9ef7fbbb4f xhci: Rename variables related to transfer descritpors
urb_priv structure has a count on how many TDs the
URB contains, and how many of those TD's we have handled.

rename:
length -> num_tds
td_cnt -> num_tds_done

No functional changes

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:00:02 +01:00
Felipe Balbi 5abdc2e6e1 usb: host: xhci: add urb_enqueue/dequeue/giveback tracers
These three new tracers will help us tie TRBs into URBs by *also*
looking into URB lifetime.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:00:01 +01:00
Felipe Balbi a37c3f76e6 usb: host: xhci: make a generic TRB tracer
instead of having a tracer that can only trace command completions,
let's promote this tracer so it can trace and decode any TRB.

With that, it will be easier to extrapolate the lifetime of any TRB
which might help debugging certain issues.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 11:00:01 +01:00
Felipe Balbi a54cfae3c7 usb: host: xhci: convert to list_for_each_entry_safe()
instead of using while(!list_empty()) followed by list_first_entry(), we
can actually use list_for_each_entry_safe().

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:07 +01:00
Mathias Nyman 5278204c98 xhci: use the trb_to_noop() helper for command trbs
Remove duplicate code by using trb_to_noop() when
handling Aborted commads

Based on earlier code by Felipe Balbi <felipe.balbi@linux.intel.com>

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:07 +01:00
Mathias Nyman ae1e3f0732 xhci: Introduce helper to turn one TRB into a no-op
Useful for turning both transfer and command trbs
into no-ops.

Based on earlier code by Felipe Balbi <felipe.balbi@linux.intel.com>

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:07 +01:00
Felipe Balbi a60f2f2ffa usb: host: xhci: unconditionally call xhci_unmap_td_bounce_buffer()
xhci_unmap_td_bounce_buffer() already checks for a valid td->bounce_seg
and bails out early if that's invalid. There's no need to check for this
twice.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Felipe Balbi f45e2a0211 usb: host: xhci: check for a valid ring when unmapping bounce buffer
This way we can remove checks for valid ring from call sites of
xhci_unmap_td_bounce_buffer()

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Felipe Balbi f3899a28e2 usb: host: xhci: remove bogus __releases()/__acquires() annotation
handle_tx_event() is not releasing xhci->lock nor reacquiring it, remove
the bogus annotation.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Felipe Balbi 55fa4396b2 usb: host: xhci: introduce xhci_td_cleanup()
By extracting xhci_td_cleanup() from finish_td(), code before clearer
and easier to follow.

There are no functional changes with this patch. It's merely a cleanup.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Felipe Balbi be0f50c2e3 usb: host: xhci: reorder variable definitions
no functional changes. Simple cleanup to make sure variables are ordered
in a 'reverse christmas tree' fashion. While at that, also remove an
obsolete comment which doesn't apply anymore.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Felipe Balbi 04861f8336 usb: host: xhci: use slightly better list helpers
Replace list_entry() with list_first_entry() and list_for_each() with
list_for_each_entry(). This makes the code slightly more readable.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Felipe Balbi 76a35293b9 usb: host: xhci: simplify irq handler return
Instead of having several return points, let's use a local variable and
a single place to return. This makes the code slightly easier to read.

[set ret = IRQ_HANDLED in default working case  -Mathias]
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Felipe Balbi 0b7c105a04 usb: host: xhci: rename completion codes to match spec
Cleanup only. This patch is a mechaninal rename to make sure our macros
for TRB completion codes match what the specification uses to refer to
such errors. The idea behind this is that it makes it far easier to grep
the specification and match it with implementation.

Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:59:06 +01:00
Lu Baolu daa47f2132 usb: xhci: use list_is_singular for cmd_list
Use list_is_singular() to check if cmd_list has only one entry.

[use list_empty() in queue command instead -Mathias]
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:35 +01:00
Lu Baolu fb79a6da45 usb: xhci: avoid unnecessary calculation
No need to calculate remainder and length_field, if there is
no data phase of a control transfer.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:35 +01:00
Lu Baolu 80c479622f usb: xhci: remove unnecessary assignment
Drop an unnecessary assignment in prepare_transfer().

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:35 +01:00
Lu Baolu 1cc6d8617b usb: xhci: remove unnecessary second abort try
The second try was a workaround for (what we thought was) command
ring failing to stop in the first place. But this turns out to be
due to the race that we have fixed(see "xhci: Fix race related to
abort operation"). With that fix, it is time to remove the second
try.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:35 +01:00
Mathias Nyman 6b02e97491 xhci: remove unnecessary check for pending timer
Checking if the command timeout timer is pending when queueing the
first command to the command ring is not really useful, remove it.

Suggested-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:35 +01:00
Mathias Nyman f99265965b xhci: detect stop endpoint race using pending timer instead of counter.
A counter was used to find out if the stop endpoint completion raced with
the stop endpoint timeout timer. This was needed in case the stop ep
completion failed to delete the timer as it was running on anoter cpu.

The EP_STOP_CMD_PENDING flag was not enough as a new stop endpoint command
may be queued between the command completion and timeout function, which
would set the flag back.

Instead of the separate counter that was used we can detect the race by
checking both the STOP_EP_PENDING flag and timer_pending in the timeout
function.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:34 +01:00
Mathias Nyman 9983a5fc39 xhci: rename EP_HALT_PENDING to EP_STOP_CMD_PENDING
We don't want to confuse halted and stalled endpoint states with
a flag indicating we are waiting for a stop endpoint command to
finish or timeout

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:34 +01:00
Mathias Nyman 505f581c48 xhci: simplify if statement to make it more readable
No functional change, De Morgan !(A && B) = (!A || !B)

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 10:57:34 +01:00
Mathias Nyman d6169d0409 xhci: fix deadlock at host remove by running watchdog correctly
If a URB is killed while the host is removed we can end up in a situation
where the hub thread takes the roothub device lock, and waits for
the URB to be given back by xhci-hcd, blocking the host remove code.

xhci-hcd tries to stop the endpoint and give back the urb, but can't
as the host is removed from PCI bus at the same time, preventing the normal
way of giving back urb.

Instead we need to rely on the stop command timeout function to give back
the urb. This xhci_stop_endpoint_command_watchdog() timeout function
used a XHCI_STATE_DYING flag to indicate if the timeout function is already
running, but later this flag has been taking into use in other places to
mark that xhci is dying.

Remove checks for XHCI_STATE_DYING in xhci_urb_dequeue. We are still
checking that reading from pci state does not return 0xffffffff or that
host is not halted before trying to stop the endpoint.

This whole area of stopping endpoints, giving back URBs, and the wathdog
timeout need rework, this fix focuses on solving a specific deadlock
issue that we can then send to stable before any major rework.

Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-11 16:52:13 +01:00
Felipe Balbi 29fc1aa454 usb: host: xhci: handle COMP_STOP from SETUP phase too
Stop Endpoint command can come at any point and we
have no control of that. We should make sure to
handle COMP_STOP on SETUP phase as well, otherwise
urb->actual_length might be set to negative values
in some occasions such as below:

 urb->length = 4;
 build_control_transfer_td_for(urb, ep);

 					stop_endpoint(ep);

COMP_STOP:
	[...]
	urb->actual_length = urb->length - trb->length;

trb->length is 8 for SETUP stage (8 control request
bytes), so actual_length would be set to -4 in this
case.

While doing that, also make sure to use TRB_TYPE
field of the actual TRB instead of matching pointers
to figure out in which stage of the control transfer
we got our completion event.

Cc: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-03 17:37:32 +01:00
OGAWA Hirofumi 1c111b6c38 xhci: Fix race related to abort operation
Current abort operation has race.

    xhci_handle_command_timeout()
      xhci_abort_cmd_ring()
        xhci_write_64(CMD_RING_ABORT)
        xhci_handshake(5s)
	  do {
	    check CMD_RING_RUNNING
            udelay(1)
					 ...
					 COMP_CMD_ABORT event
					 COMP_CMD_STOP event
					 xhci_handle_stopped_cmd_ring()
					   restart cmd_ring
                                           CMD_RING_RUNNING become 1 again
	  } while ()
          return -ETIMEDOUT
        xhci_write_64(CMD_RING_ABORT)
        /* can abort random command */

To do abort operation correctly, we have to wait both of COMP_CMD_STOP
event and negation of CMD_RING_RUNNING.

But like above, while timeout handler is waiting negation of
CMD_RING_RUNNING, event handler can restart cmd_ring. So timeout
handler never be notice negation of CMD_RING_RUNNING, and retry of
CMD_RING_ABORT can abort random command (BTW, I guess retry of
CMD_RING_ABORT was workaround of this race).

To fix this race, this moves xhci_handle_stopped_cmd_ring() to
xhci_abort_cmd_ring().  And timeout handler waits COMP_CMD_STOP event.

At this point, timeout handler is owner of cmd_ring, and safely
restart cmd_ring by using xhci_handle_stopped_cmd_ring().

[FWIW, as bonus, this way would be easily extend to add CMD_RING_PAUSE
operation]

[locks edited as patch is rebased on other locking fixes -Mathias]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-03 17:37:32 +01:00
OGAWA Hirofumi cb4d5ce588 xhci: Use delayed_work instead of timer for command timeout
This is preparation to fix abort operation race (See "xhci: Fix race
related to abort operation"). To make timeout sleepable, use
delayed_work instead of timer.

[change a newly added pending timer fix to pending work -Mathias]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-03 17:37:32 +01:00
Lu Baolu 4dea70778c usb: xhci: hold lock over xhci_abort_cmd_ring()
In command timer function, xhci_handle_command_timeout(), xhci->lock
is unlocked before call into xhci_abort_cmd_ring(). This might cause
race between the timer function and the event handler.

The xhci_abort_cmd_ring() function sets the CMD_RING_ABORT bit in the
command register and polling it until the setting takes effect. A stop
command ring event might be handled between writing the abort bit and
polling for it. The event handler will restart the command ring, which
causes the failure of polling, and we ever believed that we failed to
stop it.

As a bonus, this also fixes some issues of calling functions without
locking in xhci_handle_command_timeout().

Cc: <stable@vger.kernel.org> # 3.7+
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-03 17:37:32 +01:00
Mathias Nyman a5a1b95141 xhci: Handle command completion and timeout race
If we get a command completion event at the same time as the command
timeout work starts on another cpu we might end up aborting the wrong
command.

If the command completion takes the xhci lock before the timeout work, it
will handle the command, pick the next command, mark it as current_cmd, and
re-queue the timeout work. When the timeout work finally gets the lock
It will start aborting the wrong command.

This case can be resolved by checking if the timeout work is pending inside
the timeout function itself. A new timeout work can only be pending if the
command completed and a new command was queued.

If there are no more commands pending then command completion will set
the current_cmd to NULL, which is already handled in the timeout work.

Cc: <stable@vger.kernel.org>
Reported-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-03 17:37:32 +01:00
Baolin Wang 2a7cfdf37b usb: host: xhci: Fix possible wild pointer when handling abort command
When current command was supposed to be aborted, host will free the command
in handle_cmd_completion() function. But it might be still referenced by
xhci->current_cmd, which need to set NULL.

Cc: <stable@vger.kernel.org>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-03 17:37:32 +01:00