Re: [PATCH] x86: Fix S4 regression

[Takashi Iwai <tiwai@suse.de>]

At Sun, 23 Oct 2011 17:29:24 -0700,
Yinghai Lu wrote:
> 
> On 10/23/2011 02:19 PM, Takashi Iwai wrote:
> 
> > The commit 4b239f458: [x86-64, mm: Put early page table high] causes
> > a S4 regression since 2.6.39, namely the machine reboots occasionally
> > at S4 resume.  It doesn't happen always, overall rate is about 1/20.
> > But, like other bugs, once when this happens, it continues to happen.
> > 
> > This patch fixes the problem by essentially reverting the memory
> > assignment in the older way.
> > 
> > Cc: <stable@kernel.org>
> > Signed-off-by: Takashi Iwai <tiwai@suse.de>
> > 
> > ---
> > I resend this as a "fix" patch now before it's forgotten and rotten.
> > It's just papering again over the mystery, but IMO better than the
> > hard-reset behavior as of now.  Unfortunately, bisection is pretty 
> > much difficult because the bug itself is fairly unstable...
> 
> 
> 
> Did you try to check several commit that Rafael pointed out:
> 
> 
> On Wed, Sep 28, 2011 at 12:30 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Wednesday, September 28, 2011, Takashi Iwai wrote:
> >>
> >> If my previous test -- 2.6.37+Yinghai's patches didn't show the
> >> problem -- is correct, it means that some change in 2.6.38 reacted
> >> badly with Yinghai's patches, not about 2.6.39.  I'll check tomorrow
> >> again whether this observation is really correct.
> >
> > Yes, that would be good to know, thanks for doing this!
> >
> > If that turns out to be the case, there are the following commits
> > looking like worth checking:
> >
> > d344e38 x86, nx: Mark the ACPI resume trampoline code as +x
> > 884b821 ACPI: Fix acpi_os_read_memory() and acpi_os_write_memory() (v2)
> > d551d81 ACPI / PM: Call suspend_nvs_free() earlier during resume
> > 2d6d9fd ACPI: Introduce acpi_os_ioremap()

Yes, but these are harmless, as far as I've tested.


Takashi