[PATCH 3/6] ALSA: usb-audio: Add PM guard to Scarlett meter reads
Will Porter <[email protected]>
| Newsgroups | gmane.linux.kernel,gmane.linux.sound |
|---|---|
| Message-ID | <[email protected]> |
The Scarlett Gen 1 meter callback reads the device without preventing runtime suspend or disconnect. The transfer can fail when userspace polls the volatile control after the device suspends. Hold snd_usb_lock across the meter request. This matches the guarded Forte and common mixer control paths in this file. Assisted-by: Codex:gpt-5.6-sol Signed-off-by: Will Porter <[email protected]> --- sound/usb/mixer_scarlett.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sound/usb/mixer_scarlett.c b/sound/usb/mixer_scarlett.c index 673eb8d8724d..369968565c19 100644 --- a/sound/usb/mixer_scarlett.c +++ b/sound/usb/mixer_scarlett.c @@ -707,6 +707,10 @@ static int scarlett_ctl_meter_get(struct snd_kcontrol *kctl, int idx = snd_usb_ctrl_intf(elem->head.mixer->hostif) | (elem->head.id << 8); int err; + CLASS(snd_usb_lock, pm)(chip); + if (pm.err < 0) + return -EIO; + err = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), UAC2_CS_MEM, -- 2.47.3