[PATCH][SRU][Xenial] Fix can't disable USB port issue

[Colin Ian King]

On 22/06/17 09:51, AceLan Kao wrote:
> BugLink: http://bugs.launchpad.net/bugs/1695216
> 
> [Impact]
> In BIOS, there is front USB port disable function.
> It is supposed the option in BIOS can disable USB port, but due to AMD chip's
> limitation, it needs OS’s cowork. Otherwise the USB disable function will
> be invalid when resuming from S3 or reinsert USB device.
> 
> [Fix]
> After checking with Windows, we found there are 2 bits that are default on
> in Ubuntu is disabled in Windows. They are 
> 	#define PORT_WKOC_E     (1<<22)         /* wake on overcurrent (enable) */
> 	#define PORT_WKCONN_E   (1<<20)         /* wake on connect (enable) */
> So, this patch introduce a quirk to not setup the wakeup bits only for
> AMD USB chips.
> 
> [Test]
> Verified on the machine has this issue, and confirm this patch works.
> 
> [Misc]
> This patch is accepted by the maintainer but still not shown up in any git tree
> yet. The discussion thread can be found here[1]. To fit the project schedule,
> we need this commit in our kernel as soon as possbile, and can't wait to
> next SRU release cycle.
> 
> 1. https://www.spinics.net/lists/linux-usb/msg157789.html
> 
> Jiahau Chang (1):
>   xhci: AMD Promontory USB disable port support
> 
>  drivers/usb/host/xhci-hub.c |  2 ++
>  drivers/usb/host/xhci-pci.c | 13 +++++++++++++
>  drivers/usb/host/xhci.h     |  2 ++
>  3 files changed, 17 insertions(+)
> 

As per the SRU process, please add information about the regression
potential, see: https://wiki.ubuntu.com/StableReleaseUpdates - this is
really important as it helps us know that you have considered the areas
where this could produce a regression with your fixes.

Thanks,

Colin