APPLIED: [SRU][Trusty][Vivid][Wily]xhci: Workaround to get Intel xHCI reset working more reliably

[Kamal Mostafa]

On Mon, 2015-11-23 at 02:52 +0000, Zhang, Xiong Y wrote:
> Buglink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1518816
>  
>  SRU Justification:
>  On all of Intel's shipping xHCI platforms, including both servers and
> clients, the controller can cause the shutdown process to hang.
>  This is because existing Intel xHCI controllers require a delay of 1
> mS,after setting the CMD_RESET bit in command register, before
> accessing any HC registers. This allows the HC to complete the reset
> operation and be ready for HC register access.
> Fix:
> Patch in 4.4-rc2 and cc stable kernel
> commit a5964396190d0c40dd549c23848c282fffa5d1f2
> Author: Rajmohan Mani <rajmohan.mani at intel.com>
> Date: Wed Nov 18 10:48:20 2015 +0200
>     xhci: Workaround to get Intel xHCI reset working more reliably
> Regression Potential: Just 1ms delay for xhci_reset, so regressions
> are very unlikely.
> thanks
>  

Applied to:

[ubuntu-trusty/master-next]
[ubuntu-trusty/lts-backport-utopic-next]
[ubuntu-vivid/master-next]
[ubuntu-wily/master-next]

(Not applied to ubuntu-precise, per Andy Whitcroft's comment).

 -Kamal