Re: [PATCH 25/25] ARM: pm: omap34xx: convert to generic suspend/resume support

Santosh Shilimkar
2011-06-22T23:33:42Z

On 6/22/2011 9:40 PM, Russell King - ARM Linux wrote:
> A couple of things to point out here:
>
> On Wed, Jun 22, 2011 at 04:16:58PM +0100, Russell King - ARM Linux wrote:
>> - mrc p15, 0, r4, c13, c0, 1 @ Context ID
>> - mrc p15, 0, r5, c13, c0, 2 @ User r/w thread and process ID
>> - mrc p15, 0, r6, c12, c0, 0 @ Secure or NS vector base address
>> - mrs r7, cpsr @ Store current cpsr
>> - stmia r8!, {r4-r7}
>
> 1. The User r/w thread and process ID is not saved/restored by Linux over
> context switches, so it doesn't serve any useful purpose to save and
> restore over resume.
>
It will be needed for CPUIDLE I guess.

> 2. Compare the instruction saving and restoring the vector base address
> (see below for the restore code.)
>
That's typo. It should have been mcr. Actually VBAR isn't used on GP
devices but might be used on secure devices. I know that common suspend
code doesn't consider this register. It's fine to keep it that way
and if OMAP needs it, it can save/restored outside common code.

Regards
Santosh