This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: Fix init call orders for UAC1
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-usb-audio-fix-init-call-orders-for-uac1.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5fadc941d07530d681f3b7ec91e56d8445bc3825 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Mon, 21 Aug 2023 13:18:57 +0200
Subject: ALSA: usb-audio: Fix init call orders for UAC1
From: Takashi Iwai <tiwai@xxxxxxx>
commit 5fadc941d07530d681f3b7ec91e56d8445bc3825 upstream.
There have been reports of USB-audio driver spewing errors at the
probe time on a few devices like Jabra and Logitech. The suggested
fix there couldn't be applied as is, unfortunately, because it'll
likely break other devices.
But, the patch suggested an interesting point: looking at the current
init code in stream.c, one may notice that it does initialize
differently from the device setup in endpoint.c. Namely, for UAC1, we
should call snd_usb_init_pitch() and snd_usb_init_sample_rate() after
setting the interface, while the init sequence at parsing calls them
before setting the interface blindly.
This patch changes the init sequence at parsing for UAC1 (and other
devices that need a similar behavior) to be aligned with the rest of
the code, setting the interface at first. And, this fixes the
long-standing problems on a few UAC1 devices like Jabra / Logitech,
as reported, too.
Reported-and-tested-by: Joakim Tjernlund <joakim.tjernlund@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/r/202bbbc0f51522e8545783c4c5577d12a8e2d56d.camel@xxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230821111857.28926-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/stream.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -1093,6 +1093,7 @@ static int __snd_usb_parse_audio_interfa
int i, altno, err, stream;
struct audioformat *fp = NULL;
struct snd_usb_power_domain *pd = NULL;
+ bool set_iface_first;
int num, protocol;
dev = chip->dev;
@@ -1223,11 +1224,19 @@ static int __snd_usb_parse_audio_interfa
return err;
}
+ set_iface_first = false;
+ if (protocol == UAC_VERSION_1 ||
+ (chip->quirk_flags & QUIRK_FLAG_SET_IFACE_FIRST))
+ set_iface_first = true;
+
/* try to set the interface... */
usb_set_interface(chip->dev, iface_no, 0);
+ if (set_iface_first)
+ usb_set_interface(chip->dev, iface_no, altno);
snd_usb_init_pitch(chip, fp);
snd_usb_init_sample_rate(chip, fp, fp->rate_max);
- usb_set_interface(chip->dev, iface_no, altno);
+ if (!set_iface_first)
+ usb_set_interface(chip->dev, iface_no, altno);
}
return 0;
}
Patches currently in stable-queue which might be from tiwai@xxxxxxx are
queue-5.15/alsa-usb-audio-fix-init-call-orders-for-uac1.patch
