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ALSA: usb-audio: Remove unneeded wmb() in mixer_quirks

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[ Upstream commit 9cea742559 ]

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@collabora.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Cristian Ciocaltea
2025-05-26 17:07:47 +03:00
committed by Greg Kroah-Hartman
parent 80fffa366a
commit 1847877529
1 changed files with 0 additions and 1 deletions
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1
sound/usb/mixer_quirks.c
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@@ -211,7 +211,6 @@ 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);
}