[U-Boot] [PATCH 1/2] x86: baytrail: Fix unstable ACPI S3 resume

[Bin Meng]

On Fri, Oct 13, 2017 at 7:09 PM, Stefan Roese <sr at denx.de> wrote:
> On 12.10.2017 14:07, Bin Meng wrote:
>>
>> It was observed that when booting a Ubuntu 16.04 kernel, doing ACPI
>> S3 suspend/resume sometimes causes the Ubuntu kernel hang forever.
>> The issue is however not reproduced with a kernel built from i386/
>> x86_64 defconfig configuration.
>>
>> The unstability is actually caused by unexpected interrupts being
>> generated during the S3 resume. For some unknown reason, FSP (gold4)
>> for BayTrail configures the GPIO DFX5 PAD to enable level interrupt
>> (bit 24 and 25). As this pin keeps generating interrupts during an
>> S3 resume, and there is no IRQ requester in the kernel to handle it,
>> the kernel seems to hang and does not continue resuming.
>>
>> Clear the mysterious interrupt bits for this pin.
>
>
> Thanks for working on this. This must have been very tough to debug
> and fix.
>
>> Reported-by: Stefan Roese <sr at denx.de>
>> Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
>
>
> Tested-by: Stefan Roese <sr at denx.de>
> Reviewed-by: Stefan Roese <sr at denx.de>

applied to u-boot-x86, thanks!