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

Jaroslav Kysela perex at perex.cz
Tue May 12 14:42:54 CEST 2009

On Tue, 12 May 2009, Lennart Poettering wrote:

> With my original patch there are no superfluous opens.

If application uses more *open() calls from alsa-lib for one card (for 
example to open ctl handle and pcm handle), it's better to obtain card 
index at first, because each conversion requires one or more (card id) 
open/close sequence for control device to get card_info. Providing direct 
card index eliminates this conversion. It's just suggested optimization.


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

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