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| author | Takashi Iwai <tiwai@suse.de> | 2023-06-06 11:40:35 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2023-06-06 14:34:30 +0200 |
| commit | 306f3f78a5ff578bdfd97c658a862cb2c2419fb6 (patch) | |
| tree | dee338eb0f318f33e5ba8110a61e790eca812f90 /sound/core | |
| parent | ebcbfd846367c980e105c787d372c4239e9ed922 (diff) | |
| download | linux-306f3f78a5ff578bdfd97c658a862cb2c2419fb6.tar.gz | |
ALSA: control: Keep the previous numid at snd_ctl_rename_id()
We don't need to change the numid at each time snd_ctl_rename_id() is
called, as the control element size itself doesn't change. Let's keep
the previous numid value.
Along with it, add a note about calling this function only in the
card init phase.
Reviewed-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230606094035.14808-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/control.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/sound/core/control.c b/sound/core/control.c index 82aa1af1d1d87..8386b53acdcd4 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -730,12 +730,20 @@ EXPORT_SYMBOL_GPL(snd_ctl_activate_id); * Finds the control with the old id from the card, and replaces the * id with the new one. * + * The function tries to keep the already assigned numid while replacing + * the rest. + * + * Note that this function should be used only in the card initialization + * phase. Calling after the card instantiation may cause issues with + * user-space expecting persistent numids. + * * Return: Zero if successful, or a negative error code on failure. */ int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id) { struct snd_kcontrol *kctl; + int saved_numid; down_write(&card->controls_rwsem); kctl = snd_ctl_find_id(card, src_id); @@ -743,10 +751,10 @@ int snd_ctl_rename_id(struct snd_card *card, struct snd_ctl_elem_id *src_id, up_write(&card->controls_rwsem); return -ENOENT; } + saved_numid = kctl->id.numid; remove_hash_entries(card, kctl); kctl->id = *dst_id; - kctl->id.numid = card->last_numid + 1; - card->last_numid += kctl->count; + kctl->id.numid = saved_numid; add_hash_entries(card, kctl); up_write(&card->controls_rwsem); return 0; |