Re: 2.6.25-rc2 regression - hang on suspend

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Thursday, 21 of February 2008, Soeren Sonnenburg wrote:
> On Thu, 2008-02-21 at 01:31 +0100, Rafael J. Wysocki wrote:
> > On Wednesday, 20 of February 2008, Soeren Sonnenburg wrote:
> > > On Wed, 2008-02-20 at 00:50 +0100, Rafael J. Wysocki wrote:
> > > > On Tuesday, 19 of February 2008, Soeren Sonnenburg wrote:
> > > > > On Tue, 2008-02-19 at 22:06 +0100, Rafael J. Wysocki wrote:
> > > > > > On Tuesday, 19 of February 2008, Soeren Sonnenburg wrote:
> > > > > > > Hi,
> > > > > > 
> > > > > > Hi,
> > > > > > 
> > > > > > > since 2.6.25-rc1 (first version I tried) and still in rc2
> > (and git), I
> > > > > > > see a hang on s2ram already when trying to suspend.
> > > > > > 
> > > > > > Does it work with 2.6.24?
> > > > > 
> > > > > yes.
> > > > 
> > > > Please take the current mainline (there are a couple of nasty bugs
> > fixed in
> > > > it), configure it with CONFIG_PM_DEBUG set, boot it with
> > "no_console_suspend",
> > > > run
> > > > 
> > > > # echo 8 > /proc/sys/kernel/printk
> > > > # echo devices > /sys/power/pm_test
> > > > # echo mem > /sys/power/state
> > > > 
> > > > If it hangs, it should leave a stack trace before and I need that trace to see
> > > > what's going on.  If it doesn't hang, I'll tell you what to do next.
> > > 
> > > I tried with 2.6.24.2 with CONFIG_PM_DEBUG set, following your steps and
> > > yes it works flawlessly (though the display did not come back I could
> > > suspend/resume multiple times without problems, and finally s2ram -f -p
> > > brought the display back).
> > 
> > Hm, there's no /sys/power/pm_test in 2.6.24.2 (and the "current mainline"
> > means the latest -git kernel possible or the current top of the Linus' tree),
> > so in fact you tested 2.6.24 again, that is known to work ...
> 
> Great :( 
> 
> Anyway testing linus' git-current, I see that it does not hang. However
> after the echo mem >/sys/power/state I am seeing:
> [...]
> PM: Finishing wakeup.
> Restarting tasks ... done.
> ata1: port is slow to respond, please be patient (Status 0x80)
> ata1: device not ready (errno=-16), forcing hardreset
> 
> 
> and this a couple of times. Using echo none >/sys/power/pm_test and then
> echo mem >/sys/power/state I see it hang on ata1 errors again. Waiting
> about 10-30 seconds it progresses further and finally arrives at 
> 
> CPU0 attaching NULL sched-domain
> CPU1 attaching NULL sched-domain
> 
> then hangs.

Please see if compiling the kernel with CONFIG_SMP unset makes suspend
work.

Also, if you could find the commit that broke things, it would probably help a
lot.

Thanks,
Rafael