ALSA: usb-audio: Generic application of implicit fb to Roland/BOSS devices
authorTakashi Iwai <tiwai@suse.de>
Thu, 22 Apr 2021 12:04:13 +0000 (14:04 +0200)
committerTakashi Iwai <tiwai@suse.de>
Thu, 22 Apr 2021 16:19:47 +0000 (18:19 +0200)
commit316791b556f7c4aeb7a7fea8f400f4434e71d1bf
treeaebacde545d2850fd491a087fd93be1ff433991d
parent37153cc5303aecd1ac7fc4b4b12bb93f634b4953
ALSA: usb-audio: Generic application of implicit fb to Roland/BOSS devices

Through the examinations and experiments with lots of Roland and BOSS
USB-audio devices, we found out that the recently introduced
full-duplex operations with the implicit feedback mode work fine for
quite a few devices, while the others need only the capture-side quirk
to enforce the full-duplex mode.  The recent commit d86f43b17ed4
("ALSA: usb-audio: Add support for many Roland devices' implicit
feedback quirks") tried to add such quirk entries manually in the
lists, but this turned out to be too many and error-prone, hence it
was reverted again.

This patch is another attempt to cover those missing Roland/BOSS
devices but in a more generic way.  It matches the devices with the
vendor ID 0x0582, and checks whether they are with both ASYNC sync
types or ASYNC is only for capture device.  In the former case, it's
the device with the implicit feedback mode, and applies accordingly.
In both cases, the capture stream requires always the full-duplex
mode, and we apply the known capture quirk for that, too.

Basically the already existing BOSS device quirk entries become
redundant after this generic matching, so those are removed.  Although
the capture_implicit_fb_quirks[] table became empty and superfluous, I
keep it for now, so that people can put a special device easily at any
time later again.

Link: https://lore.kernel.org/r/CAOsVg8rA61B=005_VyUwpw3piVwA7Bo5fs1GYEB054efyzGjLw@mail.gmail.com
Link: https://lore.kernel.org/r/20210414083255.9527-1-tiwai@suse.de
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=212519
Tested-by: Lucas Endres <jaffa225man@gmail.com>
Link: https://lore.kernel.org/r/20210422120413.457-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
sound/usb/implicit.c