[alsa-devel] question on snd minors
tiwai at suse.de
Tue Nov 15 12:10:42 CET 2011
At Tue, 15 Nov 2011 16:21:08 +0530,
Vinod Koul wrote:
> On Tue, 2011-11-15 at 11:12 +0100, Takashi Iwai wrote:
> > OK, if there aren't so many devices, we may still reserved slots
> > (minor 2 and 3). These can be assigned for the new type. Will be
> > there two completely different DSPs? If it's unlikely, just grab one
> > minor as the start, I'd say. You can still implement the substreams
> > in a single device.
> > Note that the above story is only for the case without
> > CONFIG_SND_DYNAMIC_MIONRS. If you use CONFIG_SND_DYNAMIC_MINORS (this
> > is usually set for all modern distros), there is no restriction but
> > the total number of minors since the minor numbers are assigned
> > dynamically. So you can forget all in the above.
> Okay thanks. I won't try to guess which options the OSes would try to
> use, so taking safer approach and ensure they work for both.
> Any case if someone doesn't like the restriction they can use
> SND_DYNAMIC_MINORS :)
Yeah, but in that case, the driver will have the limitation of free
minors anyway. Changing the static minor number assignment
(e.g. change MINORS to 64) isn't allowed at all. If any, we'd need to
extend the minors up from 256 instead of changing the existing ones.
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