Re: Resume from S2R fails after dpm_resume()

[Pavel Machek <pavel@ucw.cz>]

On Fri 2007-03-02 09:55:45, Ben Collins wrote:
> On Fri, 2007-03-02 at 15:39 +0100, Pavel Machek wrote:
> > On Fri 2007-03-02 07:25:49, Tim Gardner wrote:
> > > Pavel Machek wrote:
> > > > Hi!
> > > > 
> > > >> I instrumented 2.6.21-rc1 base/power/resume.c device_resume() with
> > > >> TRACE_RESUME(0) as the last statement in the function. Sure enough it
> > > >> was the last hash value in the RTC after a hard reboot when resume failed:
> > > >>
> > > >> [   12.028820]   hash matches drivers/base/power/resume.c:104
> > > >>
> > > >> The machine appears to be absolutely wedged after initiating resume by
> > > >> pressing the power button. The disk flashes for a half second or so,
> > > >> then thats it.
> > > >>
> > > >> It is a Dell XPS, BIOS rev A04. I'm using 'echo 1 > /sys/power/pm_trace;
> > > >> echo mem > /sys/power/state' to initiate the S2R sequence.
> > > >>
> > > >> Any suggestions on where to go from here?
> > > > 
> > > > Did it work ok in 2.6.20? Can you try to get video working/get serial
> > > > console/something?
> > > > 									Pavel
> > > 
> > > Pavel,
> > > 
> > > The last version that worked well was Ubuntu Edgy (2.6.17). It was
> > > broken by 2.6.18. I have not started the 'git bisect' process, instead
> > > I've been trying to figure out why it doesn't work in 2.6.21-rc2. Using
> > > the TRACE_RESUME macro I've drilled down to
> > > kernel/printk.c:__call_console_drivers. So far the last trace info that
> > > I have is just before the call to con->write(). I'm trying to figure out
> > > what driver has registered as the console (intel_agp or agpgart?).
> > > 
> > > Am I banging my head on a known problem?
> > 
> > 2.6.21-rc* is known broken (in more than 1 way). I'd suggest playing
> > with 2.6.20.
> 
> It's broken for him in 2.6.20 too, which led him to test 2.6.21-rc, and
> some vanilla kernels back to 2.6.18. Everything past 2.6.17 is broken
> for him.

Yep, I understood.

But 2.6.20 tends to work for people while 2.6.21-rc is broken for
people, and even broken for me (*). So I suggest to debug
2.6.20. Debugging three different problems at the same time is not
fun.

(*) timing is wrong after resume, disk spinup waits for timeout.
									Pavel
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