[alsa-devel] [PATCH] ALSA: hda_intel: disable corb rirb when single_cmd active

[Takashi Iwai]

At Wed, 04 Nov 2009 12:45:20 -0700,
Troy Kisky wrote:
> 
> Takashi Iwai wrote:
> > At Tue,  3 Nov 2009 12:22:37 -0700,
> > Troy Kisky wrote:
> >> Poulsbo(US15W) cannot have any corb registers initialized
> >> when using single_cmd mode.
> >> When send_cmd timeout occur, note error.
> > 
> > Could you be more specific?  What errors do you get?
> > 
> > And, how it goes to single_cmd mode?  The single_cmd mode is very last
> > resort, and reaching there means already a serious problem.
> > 
> > 
> > thanks,
> > 
> > Takashi
> > 
> No error messages, but the response read is always 0.

This is odd.  Something is already wrong, then.

> For testing, I passed single_cmd=1 as a modules option.
> 
> HDAudio_03.pdf says, "If implemented, these registers must not be used
> at the same time as the CORB and RIRB command/response mechanisms, as the operations
> will conflict."

I know this, but actually this never be a problem in the real
hardware.  So, it's left there.

> Plus, if the RIRB irq is enabled, the interrupt routine will print out a
> spurious interrupt message.
> 
> That said, my hardware is switching to single_cmd eventually, even if not
> passed as a module option. But at least now, when that happens my audio
> isn't dead.

It's not dead but living-dead :)
The single_cmd mode is really only for debugging.  It's never for any
running system.


thanks,

Takashi