Re: [PATCH] ALSA: hda - Add DeviceID for Haswell HDA

[Jaroslav Kysela <perex@perex.cz>]

Date 16.7.2012 10:40, Takashi Iwai wrote:
> At Fri, 13 Jul 2012 19:48:22 +0200,
> Jaroslav Kysela wrote:
>>
>>
>> 00:03.0 0403: 8086:0c0c (rev 01)
>> 	Subsystem: 8086:2010
>> --
>> 00:1b.0 0403: 8086:8c20 (rev 01)
>> 	Subsystem: 8086:7270
>>
>>
>> Perhaps, we may add also some code to penalize the HDMI only HDA bridges
>> and allocate these cards on indexes 1+ by default (implement
>> AZX_DCAPS_INDEX1) . Comments? I'll prepare a patch upon an agreement.
> 
> Having index=0 for analog would be nice in general, but I'm afraid
> that it isn't always safe in the case of HD-audio (depending on the
> implementation, though, of course): 
> 
> - BIOS may disable the analog PCI part, e.g. if a device has only
>   HDMI/DP, or vice versa.
> 
> - There are already devices showing the same problem, e.g. AMD
>   on-board with AMD D-GPU, and users may have already added index
>   option for such.
> 
> IMO, we should provide a mechanism to advertise the preferred
> configuration from the driver side without fiddling the index.
> For example, exposing an info bit that this is digital-I/O only card,
> and let alsa-lib choose another one as default (unless explicitly
> specified).

It's not a bad idea, but it would be good to have also "standard"
plughw:0 and hw:0 devices available in the system.

Do you think that the PCI ID / PCI subsystem ID check is not sufficient
to determine the hw type before the codec probe?

						Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Kernel Sound Maintainer
ALSA Project; Red Hat, Inc.