Re: stateful reconnect with snd-usb-audio

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



At Wed, 14 Jun 2006 14:19:14 +0200,
I wrote:
> 
> At Wed, 14 Jun 2006 13:37:14 +0200 (CEST),
> Jaroslav Kysela wrote:
> > 
> > On Wed, 14 Jun 2006, Takashi Iwai wrote:
> > 
> > > > As another individual pointed out a few months ago, there are some
> > > > other problems with snd-usb-audio similar to those described above.
> > > > If a certain usb audio device has open file handles and is
> > > > disconnected or the system is suspended,
> > > > snd_usb_audio_disconnect()->snd_card_free() will block in the khubd
> > > > context while ALSA waits for the file handles to be closed, preventing
> > > > khubd from doing anything else useful like processing probe requests.
> > > > Using snd_card_free_in_thread() can be just as bad as it uses
> > > > schedule_work() and blocks one of the "events" threads.  A hang in
> > > > either context can cause problems for a resume-from-RAM operation.
> > > 
> > > Hm, this has to be fixed.  Just skipping the wait for file close will
> > > solve the problem?
> > 
> > Skipping the wait means calling snd_card_free() in last fops->release(), 
> 
> No, snd_card_free() is called in disconnect callback.

I was too desnse.  You meant "a part of jobs of snd_card_free()" is
going to be executed in the last release?

Anyway, re-reading the quote above, it sounds more like a problem
happening only via suspend.  Then, this might be solved automatically
if the proper suspend/resume is implemented on usb-audio driver.


Takashi


_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.sourceforge.net/lists/listinfo/alsa-devel

[Index of Archives]     [ALSA User]     [Linux Audio Users]     [Kernel Archive]     [Asterisk PBX]     [Photo Sharing]     [Linux Sound]     [Video 4 Linux]     [Gimp]     [Yosemite News]

  Powered by Linux