Re: Problem with Avermedia 771

[Takashi Iwai <tiwai@suse.de>]

At Mon, 18 Oct 2004 15:01:14 +0200,
Gerd Knorr wrote:
> 
> On Fri, Oct 15, 2004 at 01:03:07PM +0200, Jaroslav Kysela wrote:
> > On Fri, 15 Oct 2004, Gerd Knorr wrote:
> > 
> > I think that the database should be on one central place.
> > I suggest to create a simple function in a standalone module:
> > 
> > #define BTTV_CAP_AUDIOISVIDEO	(1<<0)
> > 
> > unsigned int bttv_caps(struct pci_dev *bttv, char **name);
> 
> Hmm, I was thinking about that as well, I'm not sure it is really a good
> idea through.  We have three different different bt878 cards:
> 
>   (1) The ones where you can get audio data out of PCI function .1
>   (2) The ones which use PCI function .1 for DVB.
>   (3) The ones which use PCI function .1 for other data transfers,
>       the first WinTV PVR card for example (which isn't supported by
>       Linux at the moment, at least not the mpeg stuff).
>   (4) Cards where PCI function .1 is simply unused, i.e. you get either
>       nothing or just noise if you try to record audio from there.
> 
> I think the alsa driver should only try to use cards which fall into
> group (1), not everything but (2).  Problem with that is that it simply
> isn't known for most cards whenever they are in group (1) or (4).
> 
> There are no overlaps between the different card groups, so if every
> driver whitelists the IDs for "known-good" hardware there should be no
> overlaps between the lists (and thus no point in having a central list).
> 
> The whitelist approach would also have the advantage that you can stick
> the IDs into a struct pci_device_id list, so they will show up in
> /lib/modules/$(uname -r)/modules.pcimap, which will make the hardware
> probing easier for the distributions.

I agree with Gerd.  The whitelisting would be the easiest and the most
trustful way.  Even a new PCI entry can be added dynamically on 2.6
kernels through sysfs.

I see the device list in drivers/media/video/bttv-cards.c as mentioned
in Gerd's original post.  Which ones can be as the white list entries
for ALSA?


Takashi


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