[alsa-devel] RFC: workaround for 'azx_get_response timeout, switching to polling mode...'

[Maxim Levitsky]

On Fri, 2010-02-05 at 09:13 +0100, Takashi Iwai wrote: 
> At Thu, 04 Feb 2010 22:20:17 +0200,
> Maxim Levitsky wrote:
> > 
> > Hi,
> > 
> > Although I thought that polling mode is harmless, it sometimes isn't.
> > I found out that after few dozens of hibernate cycles, the timeout would
> > happen again kicking out first MSI, and then whole RRIB (single_cmd).
> > 
> > However, I also found out that if I resend the command that caused the
> > timeout, it would complete normally.
> > Even futher, it is possible to poll for this command, and send next
> > normally. It just works.
> > So interrupts do work, but sometimes (very rarely) are missed. It might
> > be even a hardware bug.
> > 
> > The patch I send allows to delay switch to polling till we get 3 such
> > timeouts in a row.
> > 
> > I tested this approach for about 130 hibernate cycles.
> 
> Thanks!  Applied both patches now.
> 
> I changed snd_printd() to snd_printdd() since the former is enabled on
> vendor kernels often as default, and this can worry innocent users (I
> know from my experiences :) 

Thanks a lot!

Best regards,
Maxim Levitsky