The default mixer resume code treats the errors at restoring the modified mixer items as a fatal error, and it returns back to the caller. This ends up in the resume failure, and the device will be come unavailable, although basically those errors are intermittent and can be safely ignored.

The problem itself has been present from the beginning, but it didn't hit usually because the code tries to resume only the modified items. But now with the recent commit to forcibly initialize each item at the probe time, the problem surfaced more often, hence it appears as a regression.

This patch fixes the regression simply by ignoring the errors at resume.

Fixes: b96681bd5827 ("ALSA: usb-audio: Initialize every feature unit once at probe time") Cc: stable@vger.kernel.org BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215561 Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/mixer.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 630766ba259f..a5641956ef10 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -3678,17 +3678,14 @@ static int restore_mixer_value(struct usb_mixer_elem_list *list) err = snd_usb_set_cur_mix_value(cval, c + 1, idx, cval->cache_val[idx]); if (err < 0) - return err; + break; } idx++; } } else { /* master */ - if (cval->cached) { - err = snd_usb_set_cur_mix_value(cval, 0, 0, *cval->cache_val); - if (err < 0) - return err; - } + if (cval->cached) + snd_usb_set_cur_mix_value(cval, 0, 0, *cval->cache_val); }

return 0;