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  1. 01 11月, 2011 1 次提交
  3. 20 10月, 2011 1 次提交
  5. 19 10月, 2011 5 次提交
  7. 14 10月, 2011 1 次提交
  9. 27 9月, 2011 17 次提交
  11. 21 9月, 2011 5 次提交
  13. 20 9月, 2011 2 次提交
    • A
      USB: xHCI: prevent infinite loop when processing MSE event · c2d7b49f
      由 Andiry Xu 提交于 
      When a xHC host is unable to handle isochronous transfer in the
interval, it reports a Missed Service Error event and skips some tds.

Currently xhci driver handles MSE event in the following ways:

1. When encounter a MSE event, set ep->skip flag, update event ring
   dequeue pointer and return.

2. When encounter the next event on this ep, the driver will run the
   do-while loop, fetch td from ep's td_list to find the td
   corresponding to this event.  All tds missed are marked as short
   transfer(-EXDEV).

The do-while loop will end in two ways:

1. If the td pointed by the event trb is found;

2. If the ep ring's td_list is empty.

However, if a buggy HW reports some unpredicted event (for example, an
overrun event following a MSE event while the ep ring is actually not
empty), the driver will never find the td, and it will loop until the
td_list is empty.

Unfortunately, the spinlock is dropped when give back a urb in the
do-while loop.  During the spinlock released period, the class driver
may still submit urbs and add tds to the td_list.  This may cause
disaster, since the td_list will never be empty and the loop never ends,
and the system hangs.

To fix this, count the number of TDs on the ep ring before skipping TDs,
and quit the loop when skipped that number of tds.  This guarantees the
do-while loop will end after certain number of cycles, and driver will
not be trapped in an infinite loop.
Signed-off-by: NAndiry Xu <andiry.xu@amd.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c2d7b49f
    • G
      USB: xhci: Set change bit when warm reset change is set. · 44f4c3ed
      由 Greg KH 提交于 
      Sometimes, when a USB 3.0 device is disconnected, the Intel Panther
Point xHCI host controller will report a link state change with the
state set to "SS.Inactive".  This causes the xHCI host controller to
issue a warm port reset, which doesn't finish before the USB core times
out while waiting for it to complete.

When the warm port reset does complete, and the xHC gives back a port
status change event, the xHCI driver kicks khubd.  However, it fails to
set the bit indicating there is a change event for that port because the
logic in xhci-hub.c doesn't check for the warm port reset bit.

After that, the warm port status change bit is never cleared by the USB
core, and the xHC stops reporting port status change bits.  (The xHCI
spec says it shouldn't report more port events until all change bits are
cleared.) This means any port changes when a new device is connected
will never be reported, and the port will seem "dead" until the xHCI
driver is unloaded and reloaded, or the computer is rebooted.  Fix this
by making the xHCI driver set the port change bit when a warm port reset
change bit is set.

A better solution would be to make the USB core handle warm port reset
in differently, merging the current code with the standard port reset
code that does an incremental backoff on the timeout, and tries to
complete the port reset two more times before giving up.  That more
complicated fix will be merged next window, and this fix will be
backported to stable.

This should be backported to kernels as old as 3.0, since that was the
first kernel with commit a11496eb ("xHCI: warm reset support").
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      44f4c3ed
  15. 18 9月, 2011 5 次提交
  17. 10 9月, 2011 3 次提交