This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: Ignore clock selector errors for single connection
to the 6.6-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-ignore-clock-selector-errors-for-sing.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a6c4b303d3542a5ce308f452055356c459769c1a
Author: Alexander Tsoy <alexander@xxxxxxx>
Date: Thu Feb 1 14:53:08 2024 +0300
ALSA: usb-audio: Ignore clock selector errors for single connection
[ Upstream commit eaa1b01fe709d6a236a9cec74813e0400601fd23 ]
For devices with multiple clock sources connected to a selector, we need
to check what a clock selector control request has returned. This is
needed to ensure that a requested clock source is indeed selected and for
autoclock feature to work.
For devices with single clock source connected, if we get an error there
is nothing else we can do about it. We can't skip clock selector setup as
it is required by some devices. So lets just ignore error in this case.
This should fix various buggy Mackie devices:
[ 649.109785] usb 1-1.3: parse_audio_format_rates_v2v3(): unable to find clock source (clock -32)
[ 649.111946] usb 1-1.3: parse_audio_format_rates_v2v3(): unable to find clock source (clock -32)
[ 649.113822] usb 1-1.3: parse_audio_format_rates_v2v3(): unable to find clock source (clock -32)
There is also interesting info from the Windows documentation [1] (this
is probably why manufacturers dont't even test this feature):
"The USB Audio 2.0 driver doesn't support clock selection. The driver
uses the Clock Source Entity, which is selected by default and never
issues a Clock Selector Control SET CUR request."
Link: https://learn.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers [1]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217314
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218175
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218342
Signed-off-by: Alexander Tsoy <alexander@xxxxxxx>
Link: https://lore.kernel.org/r/20240201115308.17838-1-alexander@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/usb/clock.c b/sound/usb/clock.c
index 33db334e65566..a676ad093d189 100644
--- a/sound/usb/clock.c
+++ b/sound/usb/clock.c
@@ -328,8 +328,16 @@ static int __uac_clock_find_source(struct snd_usb_audio *chip,
if (chip->quirk_flags & QUIRK_FLAG_SKIP_CLOCK_SELECTOR)
return ret;
err = uac_clock_selector_set_val(chip, entity_id, cur);
- if (err < 0)
+ if (err < 0) {
+ if (pins == 1) {
+ usb_audio_dbg(chip,
+ "%s(): selector returned an error, "
+ "assuming a firmware bug, id %d, ret %d\n",
+ __func__, clock_id, err);
+ return ret;
+ }
return err;
+ }
}
if (!validate || ret > 0 || !chip->autoclock)
