[alsa-devel] Aureal issues on resume

[Takashi Iwai]

At Fri, 16 Sep 2011 10:16:11 +0800,
Raymond Yau wrote:
> 
> 2011/9/12 Takashi Iwai <tiwai at suse.de>:
> > At Mon, 12 Sep 2011 09:53:28 +0200,
> > Takashi Iwai wrote:
> >>
> >> At Sun, 04 Sep 2011 22:32:44 +0200,
> >> Clemens Ladisch wrote:
> >> >
> >> > Raymond Yau wrote:
> >> > > The possible way is to save the contents of 128K memory mapped I/O
> >> > > ports before suspend to non-volatile memory and restore them after
> >> > > resume
> >> > >
> >> > > Is there any way for alsa driver to allocate non-volatile memory ?
> >> >
> >> > 'Normal' memory is saved over suspend.  Just use {k|v}malloc.
> >>
> >> If it's a 128kB bulk memory, vmalloc() is a more sensible choice.
> >
> > BTW, in many cases, you don't have to save/restore the whole mmio
> > region.  Instead, stop the stream, save / restore some important
> > registers and do the similar procedure for the normal prepare callback
> > in the resume, and restart the stream again.
> >
> >
> > Takashi
> >
> 
> The current au8830 alsa driver seem use less than 192Kbytes out of
> 256Kbytes mmio
> 
> http://thread.gmane.org/gmane.linux.kernel/564963/focus=47907
> 
> your patch seem initialse the request queue in figure 16 of pat 6167465
> 
> and the driver need to restore mixer and equalizer mmio for au8830 in figure 13

Yeah, that's what I mentioned in the thread.

Basically you'll need to restore the values assigned in hw_params()
for PCM.

The mixer is ac97, so it's restored by ac97_codec.c.  The rest are the
equalizer and a3d values to be restored separately.


Takashi