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

[Takashi Iwai]

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 :) 


Takashi