[PATCH 0/2] usb: xhci: correct Command Abort bit handling

[Niklas Neronin <niklas.neronin@linux.intel.com>]

Address problems with xHCI Command Abort bit handling.

First patch reworks the Command Abort procedure so that the CA bit is
asserted without modifying Command Ring Pointer under any circumstances.
It documents and corrects all previously encountered corner cases.

The second patch refines this by using writeq() for the CA write on 64-bit
architectures. Since writeq() performs a true atomic 64-bit MMIO write,
it should avoid the split-write hazards that have historically caused
Command Ring Pointer corruption.

Niklas Neronin (2):
  usb: xhci: fix Command Aborting
  usb: xhci: use writeq() for CA write on 64-bit architectures

 drivers/usb/host/xhci-ring.c | 47 ++++++++++++++++++------------------
 1 file changed, 23 insertions(+), 24 deletions(-)

-- 
2.50.1