linux/sound
Takashi Iwai 532a208ad6 ALSA: usb-audio: Avoid implicit feedback on Pioneer devices
For addressing the regression on Pioneer devices, we recently
corrected the quirk code to enable the implicit feedback mode on those
devices properly.  However, the devices still showed problems with the
full duplex operations with JACK, and after debug sessions, we figured
out that the older kernels that had worked with JACK also didn't use
the implicit feedback mode at all although they had the quirk code to
enable it; instead, the old code worked just to skip the normal sync
endpoint setup that would have been detected without it.  IOW, what
broke without the implicit-fb quirk in the past was the application of
the normal sync endpoint that is actually the capture data endpoint on
these devices.

This patch covers the overseen piece: it modifies the quirk code again
not to enable the implicit feedback mode but just to make the driver
skipping the sync endpoint detection.  This made the driver working
with JACK full-duplex mode again.

Still it's not quite clear why the implicit feedback doesn't work on
those devices yet; maybe it's about some issues in the URB setup.  But
at least, with this patch, the driver should work in the level of the
older kernels again.

Fixes: 167c9dc84e ("ALSA: usb-audio: Fix implicit feedback sync setup for Pioneer devices")
Link: https://lore.kernel.org/r/20210118075816.25068-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-01-18 09:38:13 +01:00
..
ac97
aoa
arm
atmel
core ALSA: seq: oss: Fix missing error check in snd_seq_oss_synth_make_info() 2021-01-15 10:35:17 +01:00
drivers ALSA: aloop: Constify ops structs 2020-11-21 09:30:35 +01:00
firewire ALSA: firewire-tascam: Fix integer overflow in midi_port_work() 2021-01-12 14:57:38 +01:00
hda Auxiliary Bus support tag for 5.11-rc1 2020-12-04 20:39:45 +00:00
i2c
isa ALSA: sb: Fix fall-through warnings for Clang 2020-11-21 09:29:26 +01:00
mips
oss
parisc
pci ALSA: hda: Add Cometlake-R PCI ID 2021-01-15 11:15:53 +01:00
pcmcia
ppc powerpc updates for 5.11 2020-12-17 13:34:25 -08:00
sh
soc ASoC: AMD Renoir - add DMI entry for Lenovo ThinkPad X395 2020-12-28 14:22:44 +00:00
sparc
spi
synth
usb ALSA: usb-audio: Avoid implicit feedback on Pioneer devices 2021-01-18 09:38:13 +01:00
x86
xen
ac97_bus.c
Kconfig
last.c
Makefile
sound_core.c