linux-kernel - Re: The snd-aw2 audio driver conflicts with saa7146-based video adapters

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Date:	Thu, 16 Oct 2008 07:51:30 +0200
From:	Takashi Iwai <tiwai@...e.de>
To:	Cédric Brégardis <cedric.bregardis@...e.fr>
Cc:	Chuck Ebbert <cebbert@...hat.com>, jhassler@...e.fr,
	linux-kernel@...r.kernel.org
Subject: Re: The snd-aw2 audio driver conflicts with saa7146-based video adapters

At Wed, 15 Oct 2008 23:07:29 +0200,
Cédric Brégardis wrote:
> 
> Le Tuesday 14 October 2008, Takashi Iwai a écrit :
> > At Mon, 13 Oct 2008 19:59:23 -0400,
> >
> > Chuck Ebbert wrote:
> > > snd-aw2 ("Emagic Audiowerk 2 sound driver") matches on PCI ID for any
> > > board containing an saa7146 chip. When the driver loads it blocks the
> > > proper driver from loading. It also blindly assumes that it is driving an
> > > aw2 adapter and just starts writing to various I/O ports...
> >
> > Indeed, that's bad.
> > I guess simply adding PCI SSID would solve this (hopefully).
> >
> > Cedric, Jean, could you show "lspci -nv" output of the AW2 device?
> > (more better submit a patch? :)
> 
> Here is lspci -nv for aw2:
> 
> 02:0b.0 0480: 1131:7146 (rev 01)
>         Flags: medium devsel, IRQ 19
>         Memory at feafbc00 (32-bit, non-prefetchable) [size=512]
> 
> And here is lspci -x:
> 
> 02:0b.0 Multimedia controller: Philips Semiconductors SAA7146 (rev 01)
> 00: 31 11 46 71 02 00 80 02 01 00 80 04 00 40 00 00
> 10: 00 bc af fe 00 00 00 00 00 00 00 00 00 00 00 00
> 20: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 30: 00 00 00 00 00 00 00 00 00 00 00 00 0b 01 00 00
> 
> So, the subsystem id and subsystem vendor id is 0, which is the default value 
> for SAA7146. SAA7146 can be configured to use a specific subid with an eeprom, 
> but it is not done here. However we can verify that the subid is zero. It is 
> not a perfect solution, but it is better than nothing. I will try to provide a 
> patch next week.

Hrm, then maybe it doesn't help much, unfortunately.

> However what can we do if there is another card with SAA7146 and with the 
> default subid which is not the aw2 sound card ?

The other drivers try to detect the hardware and returns the error in
probe, thus the system can continue to probe the next driver.  aw2
driver assumes that it must be an AW2.

Is there any way to detect AW2 hardware properly?


thanks,

Takashi
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