[alsa-devel] ALSA hang on 4.13.0-rc7

[Takashi Iwai]

On Wed, 30 Aug 2017 13:42:41 +0200,
Markus Trippelsdorf wrote:
> 
> On 2017.08.30 at 13:34 +0200, Takashi Iwai wrote:
> > On Wed, 30 Aug 2017 13:33:40 +0200,
> > Markus Trippelsdorf wrote:
> > > 
> > > On 2017.08.30 at 13:23 +0200, Takashi Iwai wrote:
> > > > On Wed, 30 Aug 2017 12:03:34 +0200,
> > > > Markus Trippelsdorf wrote:
> > > > > 
> > > > > On my system ALSA sometimes hangs:
> > > > > 
> > > > >  sysrq: SysRq : Show Blocked State                                         
> > > > >    task                        PC stack   pid father                       
> > > > >  output:ALSA def D    0   171      1 0x00000000                            
> > > > >  Call Trace:                  
> > > > >   ? __schedule+0x17c/0x720    
> > > > >   ? schedule_preempt_disabled+0x2d/0x80                                    
> > > > >   ? __mutex_lock_slowpath+0x141/0x420                                      
> > > > >   ? snd_pcm_common_ioctl1+0x2f/0x1400                                      
> > > > >   ? snd_pcm_common_ioctl1+0x2f/0x1400                                      
> > > > >   ? snd_card_file_remove+0x76/0x120                                        
> > > > >   ? snd_pcm_playback_ioctl+0x1c7/0x560                                     
> > > > >   ? dput+0xb6/0x1e0           
> > > > >   ? SyS_ioctl+0xa7/0x860      
> > > > >   ? task_work_run+0x70/0xa0   
> > > > >   ? entry_SYSCALL_64_fastpath+0x13/0x94  
> > > > > 
> > > > > Only a reboot will fix the issue.
> > > > 
> > > > Is this a regression?
> > > 
> > > Yes. 4.11 is fine.
> > 
> > And 4.12?
> 
> Just build it and yes 4.12 is fine, too.
> 
> (Before you ask, I have intention to bisect the issue.
> It would be too annoying with the all the required reboots.

That'd be really appreciated.  We had lots of changes since 4.12
regarding PCM core stuff, so narrowing down would be a great help.

> But if you want I can run scripts/faddr2line on the backtraces.)

Let's try to narrow at first a bit.  For such a problem, the trace
itself is often too late, not the cause itself.


thanks,

Takashi