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From: Sasha Levin <sashal@kernel.org>
To: olivier.kaloudoff@gmail.com, tiwai@suse.de
Cc: stable@vger.kernel.org
Subject: FAILED: patch "[PATCH] ALSA: usb-audio: Add mic resolution quirk for Logitech Webcam C200" failed to apply to 5.10-stable tree
Date: Sat,  7 Nov 2026 06:20:07 -0500	[thread overview]
Message-ID: <20261107062007-failed-5.10-874323b68c93@kernel.org> (raw)

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 874323b68c93c6808e034dc0113681e822e6fb42
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107062007-failed-5.10-874323b68c93@kernel.org' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From 874323b68c93c6808e034dc0113681e822e6fb42 Mon Sep 17 00:00:00 2001
From: Olivier Kaloudoff <olivier.kaloudoff@gmail.com>
Date: Fri, 9 Oct 2026 01:08:44 +0200
Subject: [PATCH] ALSA: usb-audio: Add mic resolution quirk for Logitech Webcam
 C200

The C200 (046d:0802) reports a mic capture volume range of
1536..7680 with a resolution of 1 (6144 steps), triggering
"Warning! Unlikely big volume step count (=6144), linear volume or
wrong cval->res?" at probe and exposing a uselessly fine-grained
mixer control.  This is the same firmware behavior as the other
UVC-era Logitech webcams already carrying QUIRK_FLAG_MIC_RES_384
(C500, C600, C210, C270, C310, C510, C525, ...), so apply the same
quirk: CTL_MSG_DELAY_1M (which the Logitech VENDOR_FLG would provide
if the device-specific entry did not short-circuit the lookup) plus
MIC_RES_384.

Verified on real hardware: with the quirk the warning disappears and
the driver logs "set resolution quirk: cval->res = 384".

Signed-off-by: Olivier Kaloudoff <olivier.kaloudoff@gmail.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20261008230844.11246-1-olivier.kaloudoff@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/usb/quirks.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 170f68db74fa4..7a5c95de86ceb 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -2494,6 +2494,8 @@ static const struct usb_audio_quirk_flags_table quirk_flags_table[] = {
 		   QUIRK_FLAG_DISABLE_AUTOSUSPEND),
 	DEVICE_FLG(0x045e, 0x070f, /* MS LifeChat LX-3000 Headset */
 		   QUIRK_FLAG_MIXER_PLAYBACK_MIN_MUTE),
+	DEVICE_FLG(0x046d, 0x0802, /* Logitech Webcam C200 */
+		   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
 	DEVICE_FLG(0x046d, 0x0807, /* Logitech Webcam C500 */
 		   QUIRK_FLAG_CTL_MSG_DELAY_1M | QUIRK_FLAG_MIC_RES_384),
 	DEVICE_FLG(0x046d, 0x0808, /* Logitech Webcam C600 */
-- 
2.53.0





             reply	other threads:[~2026-11-07 11:20 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-07 11:20 Sasha Levin [this message]
2026-11-10 16:04 ` [PATCH 5.10.y] ALSA: usb-audio: Add mic resolution quirk for Logitech Webcam C200 Sasha Levin

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