Comment 29 for bug 8050

(In reply to comment #25)
> Perhaps it would suffice if we made a list of drivers that drive
> cards that are inherently unsuitable to be the primary sound card.
> I take it that snd-bt87x is such a driver because it only does
> recording, no playback. There may be others (e.g., the modems?).
> For each of these drivers we could add lines like these to
> /etc/mod(utils|probe.d)/alsa-base:
>
> options snd-bt87x index=1
>
> so that they don't get assigned index 0.
>
> This scheme has a weakness. If the "index" option is not used
> then ALSA assigns the first available index. If the "index"
> option _is_ used the ALSA does not assign the first available
> index; it only tries to assign the specified index and fails
> if that index is already taken. Our scheme would be better if
> we could get ALSA to implement a feature like this:
>
> options snd-bt87x index=1-
>
> where "1-" means "1 or higher". However, even without this
> enhancement I think that excluding the drivers in question from
> getting index 0 is more important than supporting systems that
> have three or more sound cards.
>
> Comments?

I think this would address the bulk of the problem in as simple way, and so I
quite like the idea.

Are the existing semantics of "I must use index N" useful enough that we should
not just override index=N to mean "N or higher"? That seems reasonable to me.