diff options
| author | Cássio Gabriel <cassiogabrielcontato@gmail.com> | 2026-04-21 21:53:52 -0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2026-04-22 17:51:42 +0200 |
| commit | fca9c850042a7ab4828ce3a9caa8bc40ea09856a (patch) | |
| tree | 4ffb4d32b409cc2c73116a57edea3fb7fb026cdc | |
| parent | eacda758e3c01db98b5c231f56cf9a6e05ced75c (diff) | |
ALSA: usb-audio: Avoid false E-MU sample-rate notifications
snd_emuusb_set_samplerate() unconditionally notifies the E-MU
SampleRate Extension Unit control after issuing SET_CUR.
If snd_usb_mixer_set_ctl_value() fails, the control value has not
changed, yet snd_usb_mixer_notify_id() still invalidates the cache and
emits a value-change event to userspace.
Notify the control only after a successful write.
Fixes: 7d2b451e65d2 ("ALSA: usb-audio - Added functionality for E-mu 0404USB/0202USB/TrackerPre")
Cc: stable@vger.kernel.org
Signed-off-by: Cássio Gabriel <cassiogabrielcontato@gmail.com>
Link: https://patch.msgid.link/20260421-alsa-emuusb-samplerate-notify-v1-1-8b63bbc1d7f1@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/usb/mixer_quirks.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index a01510a855c2..5194a2ac1ea8 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -1538,15 +1538,17 @@ void snd_emuusb_set_samplerate(struct snd_usb_audio *chip, { struct usb_mixer_interface *mixer; struct usb_mixer_elem_info *cval; + int err; int unitid = 12; /* SampleRate ExtensionUnit ID */ list_for_each_entry(mixer, &chip->mixer_list, list) { if (mixer->id_elems[unitid]) { cval = mixer_elem_list_to_info(mixer->id_elems[unitid]); - snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, - cval->control << 8, - samplerate_id); - snd_usb_mixer_notify_id(mixer, unitid); + err = snd_usb_mixer_set_ctl_value(cval, UAC_SET_CUR, + cval->control << 8, + samplerate_id); + if (!err) + snd_usb_mixer_notify_id(mixer, unitid); break; } } |