[alsa-devel] [PATCH 1/5] allow up to 32 PCM devices

[Wu Fengguang]

On Fri, May 14, 2010 at 04:21:09PM +0800, Takashi Iwai wrote:
> At Thu, 13 May 2010 10:21:26 +0800,
> Wu Fengguang wrote:
> > 
> > On Wed, May 12, 2010 at 06:55:09PM +0800, Takashi Iwai wrote:
> > > At Wed, 12 May 2010 12:20:33 +0200,
> > > Clemens Ladisch wrote:
> > > > 
> > > > Takashi Iwai wrote:
> > > > > Wu Fengguang wrote:
> > > > > > > Jaroslav Kysela wrote:
> > > > > > > > I don't agree to have only 4 slots for soundcards in the static minor 
> > > > > > > > numbering. Maybe the driver should be converted to use subdevices or we 
> > > > > > > > might drop the static minor number allocation at all (it might have only 
> > > > > > > > impact for old distros).
> > > > > > 
> > > > > > Jaroslav, will there be so many sound cards in one system?
> > > > > 
> > > > > In the old time, yes.  Now we have less and less PCI slots.
> > > > > In theory, we may have lots of USB audio devices, though :)
> > > > 
> > > > I implemented CONFIG_SND_DYNAMIC_MINORS because people had been asking
> > > > for more than eight cards.  (And by now I have lots of cards too,
> > > > although my computer probably isn't very typical.)
> > > > 
> > > > Anyway, static numbering is needed only for systems without udev/devfs,
> > > > and there we shouldn't change it for backwards compatibility.  The HDA
> > > > driver already requires kernels >= 2.6, so I don't see a problem with
> > > > requiring CONFIG_SND_DYNAMIC_MINORS to get all HDMI outputs.
> > > 
> > > Right.  We can make it dependent.
> > > 
> > 
> > Like this?
> > 
> >  config SND_HDA_CODEC_INTELHDMI
> >  	bool "Build INTEL HDMI HD-audio codec support"
> > +	select SND_DYNAMIC_MINORS
> >  	default y
> > 
> > That will effectively turn on CONFIG_SND_DYNAMIC_MINORS by default
> > (distribution kernels will have to enable it).
> 
> It's always a question whether we use "depends on" or "select".
> The former is safer while the latter is more intuitive.
> 
> In this particular case, I think "select" would be OK.
> If other guys have no objection, please repost the patch so that I can
> pick it up later.

OK. Wait a minute :)

> > Another backwards compatible solution is to fall back to the two
> > reserved values. This makes me a bit more comfortable :)
> 
> As mentioned in another post, I don't see a big merit by it.
> In short: don't touch a working code :)  The non-dynamic minors are
> only for old stuff, better to keep as is.

OK. I'll drop that idea.

Thanks,
Fengguang