linux/sound
Takashi Iwai b96681bd58 ALSA: usb-audio: Initialize every feature unit once at probe time
So far we used to read the current value of the mixer element
dynamically at the first access, and the error from a GET_CUR message
is treated as a fatal error (unless QUIRK_IGNORE_CTL_ERROR is set).
It's rather inconvenient, as most of GET_CUR errors are no fatal, and
we can continue operation with assumption of some fixed value.

This patch makes the USB-audio driver to change the behavior at probe
time; now it tries to initialize the current value of each mixer
element that is built from a feature unit (those for typically for
mixer volumes and switches).  When a read failure happens, it tries to
set the known minimum value.  After that point, a cached value is used
always, hence we won't hit GET_CUR message error any longer.

The error from GET_CUR message is still shown as a warning normally,
but only once at the probe time, and it'll keep operating.  If the
message is confirmed to be harmless, it can be shut up by
QUIRK_IGNORE_CTL_ERROR quirk flag, too.

Tested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20211014130636.17860-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-10-14 16:51:56 +02:00
..
ac97 bus: Make remove callback return void 2021-07-21 11:53:42 +02:00
aoa Kbuild updates for v5.15 2021-09-03 15:33:47 -07:00
arm ALSA: pxa2xx: Use managed PCM buffer allocation 2021-08-04 08:08:21 +02:00
atmel
core Merge branch 'for-linus' into for-next 2021-10-14 15:54:30 +02:00
drivers ALSA: pcsp: Make hrtimer forwarding more robust 2021-09-28 10:58:08 +02:00
firewire ALSA: firewire-motu: fix truncated bytes in message tracepoints 2021-09-21 18:48:32 +02:00
hda Merge branch 'for-linus' into for-next 2021-10-14 15:54:30 +02:00
i2c ALSA: i2c: tea6330t: Remove redundant initialization of variable err 2021-06-12 09:32:14 +02:00
isa ALSA: gus: Fix repeated probe for ISA interwave card 2021-09-07 11:40:08 +02:00
mips ALSA: n64: check return value after calling platform_get_resource() 2021-06-12 09:31:13 +02:00
oss sound/oss/dmasound: Remove superfluous "break" 2021-05-27 08:24:23 +02:00
parisc parisc architecture updates for kernel 5.15: 2021-09-02 13:16:00 -07:00
pci Merge branch 'for-linus' into for-next 2021-10-14 15:54:30 +02:00
pcmcia ALSA: vx: Manage vx_core object with devres 2021-07-19 16:17:09 +02:00
ppc ALSA: ppc: fix error return code in snd_pmac_probe() 2021-06-16 08:52:29 +02:00
sh module: remove never implemented MODULE_SUPPORTED_DEVICE 2021-03-17 13:16:18 -07:00
soc Merge branch 'for-linus' into for-next 2021-10-14 15:54:30 +02:00
sparc ALSA: sparc: Fix assignment in if condition 2021-06-09 17:30:29 +02:00
spi
synth ALSA: emux: fix spelling mistakes 2021-07-05 19:34:22 +02:00
usb ALSA: usb-audio: Initialize every feature unit once at probe time 2021-10-14 16:51:56 +02:00
virtio ALSA: virtio: Replace zero-length array with flexible-array member 2021-09-30 13:47:57 +02:00
x86 ALSA: memalloc: Correctly name as WC 2021-08-04 08:07:58 +02:00
xen module: remove never implemented MODULE_SUPPORTED_DEVICE 2021-03-17 13:16:18 -07:00
ac97_bus.c
Kconfig ALSA: virtio: add virtio sound driver 2021-03-07 09:07:16 +01:00
last.c
Makefile ALSA: virtio: add virtio sound driver 2021-03-07 09:07:16 +01:00
sound_core.c