[alsa-devel] [PATCH] control, hw, rawmidi: accept control device node as card identifier when opening

Jaroslav Kysela perex at perex.cz
Tue May 12 18:54:05 CEST 2009

On Tue, 12 May 2009, Lennart Poettering wrote:

> Hmm? The first thing snd_pcm_hw_open() does is calling
> snd_ctl_hw_open(). So with your code, the name will bre resolved and
> the ctl device opened and closed for that. And then shortly after the
> device will be reopened right-away and then kept open. In my code
> after the resolving I'd just keep the device open.
> Your code requires three open()s for this, mine required two.

I see your point now - I forgot that control API is used to prefer 
subdevices. But it would be better to add some cache for ctl opens in 
alsa-lib rather than abusing other levels of API with additional 


Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.

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