[PATCH] ARM: save/restore diagnostic register on ARMv7 suspend/resume

[Nicolas Pitre]

On Wed, 18 Jun 2014, Shawn Guo wrote:

> On Wed, Jun 18, 2014 at 11:40:09AM +0100, Will Deacon wrote:
> > On Wed, Jun 18, 2014 at 09:49:58AM +0100, Shawn Guo wrote:
> > > The CP15 diagnostic register holds ARM errata bits on ARMv7, so it
> > > needs to be saved/restored on suspend/resume.  Otherwise, the
> > > effectiveness of errata workaround gets lost together with diagnostic
> > > register bit across suspend/resume cycle.
> > 
> > This should be conditional on Cortex-A9, since this register is certainly
> > not architected.
> 
> Ah, yes.  In that case, I should probably handle it at platform level to
> avoid messing up generic ARMv7 suspend/resume routines.

Please don't do that.

You may look at commit 16c79a3776 and do something similar for 
Cortex-A9.


Nicolas