Re: Debugging Thinkpad T430s occasional suspend failure.

[Dave Jones <davej@redhat.com>]

On Tue, Feb 12, 2013 at 04:26:22PM -0800, Hugh Dickins wrote:
 > On Tue, 12 Feb 2013, Dave Jones wrote:
 > 
 > > My Thinkpad T430s suspend/resumes fine most of the time. But every so often
 > > (like one in ten times or so), as soon as I suspend, I get a black screen,
 > > and a blinking power button.
 > > 
 > > (Note: Not the capslock lights like when we panic, this laptop 'conveniently
 > >  doesn't have those. This is the light surrounding the power button, which afaik
 > >  isn't even OS controlled, so maybe we're dying somewhere in SMI/BIOS land?)
 > 
 > Me too on T420s, except that is blessed with a blinking CapsLk.
 > 
 > It's so erratic (though I think I see more failures than you do: I'd say
 > a quick resume never fails, but an overnight resume fails half the time):
 > I'm afraid I didn't have the patience to embark on pm_trace at all.

Sounds like yours successfully suspends all the time though ?
For me, as soon as I shut the lid, the moon light starts flashing indicating failure.

That said, we saw that I was failing on the resume path after a failed suspend,
so it could still be the same problem.

 > I did try to bisect it during the -rc5 week.  I'm not sure, but I have
 > no record of seeing it on -rc1 or -rc2, but definitely saw it on -rc3.
 > So I tried bisecting between -rc2 and -rc3, persisting for a day if it
 > looked good; but the bisection didn't seem to be converging anywhere
 > likely when -rc6 came out, and I switched to see if -rc6 solved it.
 > 
 > I had no problem with -rc6; but with -rc7 it happens more than ever.
 > Though still not on "quick" resumes, the kind you want to do when
 > bisecting.

so I can hit this pretty quickly with this..

while [ 1 ];
do
 rtcwake -s 5 -m no ; pm-suspend
done

Which should make it bisectable at least..

 > Sharing these anecdotes in case they match or diverge from your
 > experience and others, and might help towards finding the cause.
 > Not-to-be-trusted bisection log appended: of course the bads are
 > reliable, but perhaps none of the goods.

I didn't have this laptop pre 3.8rc, so I've not had a 'good' reference,
pretty sure I saw it during rc1 though, so I might have to go back further
a version or two.

	Dave