[alsa-devel] How to deal with snooping in firmware?

[Takashi Iwai]

At Mon, 23 Sep 2013 18:37:35 +0200,
Paul Menzel wrote:
> 
> Dear ALSA folks,
> 
> 
> with Ubuntu 13.04 and AMD Kabini boards, there are audio distortions,
> which are not present under Microsoft Windows [1][2]. Disabling snooping
> fixes this, which is in line with the information from an earlier
> discussion [3].
> 
> As it works under Microsoft Windows, is this indeed a driver problem and
> should be fixed there? Is it better to disabling snooping by default in
> the firmware and let the driver enable it? What do you propose how to
> fix this?

This seems like a hardware restriction, so diasbling snooping in the
driver is the proper way to fix.  We have already the workaround for
AMD Hudson, and just need to add yet another PCI ID like 1002:aaa0.


thanks,

Takashi

> 
> 
> Thanks,
> 
> Paul
> 
> 
> [1] http://review.coreboot.org/#/c/3934/
> [2] http://review.coreboot.org/#/c/3934/1/src/mainboard/amd/olivehill/get_bus_conf.c
> [3] http://lists.freedesktop.org/archives/pulseaudio-discuss/2012-May/013568.html
>     [pulseaudio-discuss] [alsa-devel] Adjust volume may cause audio playback corruption
> 
> [2 This is a digitally signed message part <application/pgp-signature (7bit)>]
>