5.4-stable review patch. If anyone has any objections, please let me know.
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From: Cristian Ciocaltea cristian.ciocaltea@collabora.com
[ Upstream commit 9cea7425595697802e8d55a322a251999554b8b1 ]
Adding a memory barrier before wake_up() in snd_usb_soundblaster_remote_complete() is supposed to ensure the write to mixer->rc_code is visible in wait_event_interruptible() from snd_usb_sbrc_hwdep_read().
However, this is not really necessary, since wake_up() is just a wrapper over __wake_up() which already executes a full memory barrier before accessing the state of the task to be waken up.
Drop the redundant call to wmb() and implicitly fix the checkpatch complaint:
WARNING: memory barrier without comment
Signed-off-by: Cristian Ciocaltea cristian.ciocaltea@collabora.com Signed-off-by: Takashi Iwai tiwai@suse.de Link: https://patch.msgid.link/20250526-dualsense-alsa-jack-v1-8-1a821463b632@coll... Signed-off-by: Sasha Levin sashal@kernel.org --- sound/usb/mixer_quirks.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index f318b80d646d5..03d49d4c5141d 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -207,7 +207,6 @@ static void snd_usb_soundblaster_remote_complete(struct urb *urb) if (code == rc->mute_code) snd_usb_mixer_notify_id(mixer, rc->mute_mixer_id); mixer->rc_code = code; - wmb(); wake_up(&mixer->rc_waitq); }