Takashi Iwai 38ea4c3dc3 ALSA: control: Optimize locking for look-up
For a fast look-up of a control element via either numid or name
matching (enabled via CONFIG_SND_CTL_FAST_LOOKUP), a locking isn't
needed at all thanks to Xarray.  OTOH, the locking is still needed for
a slow linked-list traversal, and that's rather a rare case.

In this patch, we reduce the use of locking at snd_ctl_find_*() API
functions, and switch from controls_rwsem to controls_rwlock for
avoiding unnecessary lock inversions.  This also resulted in a nice
cleanup, as *_unlocked() version of snd_ctl_find_*() APIs can be
dropped.

snd_ctl_find_id_mixer_unlocked() is still left just as an alias of
snd_ctl_find_id_mixer(), since soc-card.c has a wrapper and there are
several users.  Once after converting there, we can remove it later.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20240809104234.8488-3-tiwai@suse.de
2024-08-09 14:24:55 +02:00
..
2024-07-25 10:42:22 -07:00
2024-07-27 10:53:06 -07:00
2024-07-25 10:42:22 -07:00
2024-07-19 12:39:34 -07:00
2024-07-25 10:42:22 -07:00