Commit 70b20dd7 authored by Linus Torvalds's avatar Linus Torvalds

ALSA: update dell-wmi mic-mute registration to new world order

Commit c647f806 ("ALSA: hda - Allow multiple ADCs for mic mute LED
controls") changed the return value of the snd_hda_gen_add_micmute_led()
without actually updating the callers.

Admittedly, almost no callers actually cared about the return value.
But one call site very much did: the Dell wmi code.  It would see the
registration return zero, which _used_ to mean "failed" but now means
"success", and clear the dell_micmute_led_set_func pointer.

End result: the successful registration would end up calling the Dell
code that thought it had all failed, and call through a NULL pointer.

To make matters worse, it ends up being a tail-call, and with the
retpoline sequence you don't even see the caller (dell_micmute_update())
in the stack trace, so the error ended up way less obvious than it
should have been.

Fixes: c647f806 "ALSA: hda - Allow multiple ADCs for mic mute LED controls"
Cc: Takashi Iwai <>
Signed-off-by: default avatarLinus Torvalds <>
parent 71f3a82f
......@@ -30,7 +30,7 @@ static void alc_fixup_dell_wmi(struct hda_codec *codec,
removefunc = (dell_micmute_led_set_func(false) < 0) ||
dell_micmute_update) <= 0);
dell_micmute_update) < 0);
if (dell_micmute_led_set_func && (action == HDA_FIXUP_ACT_FREE || removefunc)) {
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