[alsa-devel] snd_pcsp locking mess

[Takashi Iwai]

At Fri, 23 May 2008 00:28:36 +0400,
Stas Sergeev wrote:
> 
> Hello.
> 
> Takashi Iwai wrote:
> > The substream lock can be removed from hrtimer callback gracefully.
> > So, you have no longer the issue with this lock/unlock procedure.
> > In hrtimer callback, you just need to have the DMA-buffer.  That can
> > be protected without the substream lock, too, I believe.
> OK. But still, the substream have to
> be protected against the close callback.

No, close callback is always after the hw_free callback.
So, in hw_free callback, you just need to assure that hrtimer callback
is finished (and/or cancel it).  After that, you are free to work
without considering hrtimer stuff.

We don't drop pcm substream lock here because we don't need to acquire
it.

Takashi