xhci: Fix failure to give back some cached cancelled URBs.
authorMathias Nyman <mathias.nyman@linux.intel.com>
Fri, 20 Aug 2021 12:35:00 +0000 (15:35 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 12 Sep 2021 07:00:59 +0000 (09:00 +0200)
commit2fd136212dc171a3665ebb3bf0f49a14fdbc406e
treeffe11a02fbb8985dad7b31b2afb9d7e703f3fee8
parentb5671930136357c295ffa1643de7b5f5ac921c3f
xhci: Fix failure to give back some cached cancelled URBs.

commit 94f339147fc3eb9edef7ee4ef6e39c569c073753 upstream.

Only TDs with status TD_CLEARING_CACHE will be given back after
cache is cleared with a set TR deq command.

xhci_invalidate_cached_td() failed to set the TD_CLEARING_CACHE status
for some cancelled TDs as it assumed an endpoint only needs to clear the
TD it stopped on.

This isn't always true. For example with streams enabled an endpoint may
have several stream rings, each stopping on a different TDs.

Note that if an endpoint has several stream rings, the current code
will still only clear the cache of the stream pointed to by the last
cancelled TD in the cancel list.

This patch only focus on making sure all canceled TDs are given back,
avoiding hung task after device removal.
Another fix to solve clearing the caches of all stream rings with
cancelled TDs is needed, but not as urgent.

This issue was simultanously discovered and debugged by
by Tao Wang, with a slightly different fix proposal.

Fixes: 674f8438c121 ("xhci: split handling halted endpoints into two steps")
Cc: <stable@vger.kernel.org> #5.12
Reported-by: Tao Wang <wat@codeaurora.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210820123503.2605901-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/xhci-ring.c