Re: [PATCH] x86: revert "x86: Fix S4 regression"

[Takashi Iwai <tiwai@suse.de>]

At Fri, 15 Jun 2012 19:11:12 +0800,
Cong Wang wrote:
> 
> On Tue, Jun 12, 2012 at 1:21 PM, Cong Wang <amwang@redhat.com> wrote:
> >
> > Takashi, could you help to test if the S4 regression is still
> > there after this patch?
> 
> Hello,
> 
> Any comments?
> 
> I have tested this revert on my laptop, with running simple
> "suspend and resume" test for several times, I didn't see any
> problem.

Sorry for the late response.

The problem happens only on certain laptops.  I've tested the recent
IvyBridge laptops and these were OK with the reverted patch.  But a
SandyBridge laptop, the one I tested in the last year, still hits the
S4 problem with the reverted kernel.

But, the recent kernels seem to have other S4 problems on this
machine, so it's not 100% clear whether it's triggered by that.
At least, it jumpts to the boot at S4 resume more frequently when the
patch is reverted.

So, I need to start from 2.6.32 again to see what regressions have
been introduced.  It'll take time, since I'd have to S4 20 cycles
for reproducing the bug.


Takashi