Re: Oops on resume, X crashes

[Takashi Iwai <tiwai@suse.de>]

At Tue, 21 Oct 2003 16:38:44 +0800,
Bill Gou wrote:
> 
> [1  <text/plain; us-ascii (7bit)>]
> Takashi Iwai wrote:
> > At Mon, 20 Oct 2003 15:48:55 +0800,
> > Gou Zhuang wrote:
> > 
> >>I'm running kernel 2.4.22 and alsa-0.9.7c on a Dell laptop. I have problem on
> >>suspend/resume when alsa modules loaded. I have done a few testings, below is my findings:
> >>
> >>If the snd-pcm-oss module is in use(by arts sound server) at the time of suspend, kernel
> >>oops upon resuming and X server crashes. It has no problem when snd-pcm-oss is not in use(
> >>released by arts). 0.9.6 has the same behavior. My sound card is on-board intel8x0.
> >>
> >>I searched the mail archive and didn't find any similar cases. Could anybody look into
> >>this problem?
> > 
> > 
> > i don't see any obvious bugs in the resume code, and i thought it
> > worked fine once on my test machine.
> > could you check at which funciton the oops occurs, e.g. simply by
> > puttig debug printk at each entry point?  according to ksymoops, it's
> > in snd_intel8x0_resume() (i.e. intel8x0_resume()).  this could be
> > either in snd_intel8x0_chip_init() or snd_ac97_resume().
> > in the latter function, there is no sleep or no wakeup, so it's likely
> > in the former one.
> > 
> > 
> > Takashi
> > 
> I added some printks in intel8x0.c and ac97_codec.c, all printk outputs are labeled
> 'MYDEBUG'. I also enabled debug when compiling. This time I noticed the below debug
> message after resuming, it repeated for 170 times:
> 
> ALSA pcm_oss.c:552: snd_pcm_oss_prepare: SNDRV_PCM_IOCTL_PREPARE failed
 
that's strange if this message appears before snd_intel8x0_resume() is
called.  if it's after the resume() call, it's ok.


> The last function called before kernel oops is snd_power_change_state().

yes, it looks like the wake_up() in that function.
but it should be ok.  perhaps memory corruption already occured
somewhere.  anyway, try to comment out the wake_up() there.


also, please try to do suspend with the minimum setting - i.e.
no applications running but just only the drivers.


Takashi


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