[PATCH] arm:pm: save the vfp state of last scheduled-out proceed while suspending

[Barry Song]

Hi Catalin,
Thanks.
2011/4/29 Catalin Marinas <catalin.marinas at arm.com>:
> On 27 April 2011 07:30, Barry Song <bs14 at csr.com> wrote:
>> From: Rongjun Ying <rongjun.ying at csr.com>
>>
>> Current vfp pm suspend entry only saves the vfp state of running proceed if it is using vfp. If current proceed doesn't use vfp,
>> the state of last process will be lost after resume. In pressure tests, we can see old vfp processes crash after resume.
>>
>> In order that schedule can be faster, scheduler doesn't save vfp state if we schedule from proceeds using vfp to proceeds which
>> don't use vfp. If system suspend happens just at proceeds which don't use vfp, we have no any chance to save old vfp state.
>>
>> Signed-off-by: Rongjun Ying <rongjun.ying at csr.com>
>> Cc: Binghua Duan <binghua.duan at csr.com>
>> Signed-off-by: Barry Song <21cnbao at gmail.com>
>
> There was a similar patch some time ago by Colin Cross. I don't know
> what happened to it but please have a look at that discussion first:
>
> http://thread.gmane.org/gmane.linux.kernel/1099558

sorry, i didn't see any patch committed and lost the thread in lkml.

Seems like Rongjun's codes have handled Russel's last change but in
the "else". Russel handles it before the "if (fpexc & FPEXC_EN) {".
We will take over the test in
http://thread.gmane.org/gmane.linux.kernel/1099558 and continue to
send patch v3.

>
> --
> Catalin
>