linux/sound
Takashi Iwai a4aad5636c ALSA: usb-audio: Inform devices that need delayed registration
The USB-audio driver may call snd_card_register() multiple times as
its probe function is per USB interface while some USB-audio devices
may provide multiple interfaces to assign different streams although
they belong to the same device.  This works in most cases but the
registration is racy, hence it may miss the device recognition,
e.g. PA doesn't see certain devices when hotplugged.

The recent addition of the delayed registration quirk allows to sync
the registration at the last known interface, and the previous commit
added a new module option to allow the dynamic setup for that
purpose.

Now, this patch tries to find out and notifies for such devices that
require the delayed registration.  It shows a message like:

  Found post-registration device assignment: 1234abcd:02

If you hit this message, you can pass delayed_register module option
like:

  snd_usb_audio.delayed_register=1234abcd:02

by just copying the last shown entry.  If this works, it can be added
statically in the quirk list, registration_quirks[] found at the end
of sound/usb/quirks.c.

Link: https://lore.kernel.org/r/20200325103322.2508-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-26 10:49:08 +01:00
..
ac97 ALSA: ac97: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:11 +01:00
aoa ALSA: aoa: More constifications 2020-01-05 16:14:27 +01:00
arm ALSA: arm: More constification 2020-01-05 16:15:07 +01:00
atmel ALSA: atmel: Constify snd_ac97_bus_ops definitions 2020-01-03 09:24:12 +01:00
core ALSA: core: Add snd_device_get_state() helper 2020-03-23 18:09:19 +01:00
drivers ALSA: dummy: Use standard macros for fixing PCM format cast 2020-02-10 08:27:31 +01:00
firewire ALSA: firewire-tascam: Add missing annotation for tscm_hwdep_read_locked() 2020-03-11 07:55:38 +01:00
hda ALSA: hda: Use scnprintf() for string truncation 2020-03-13 15:59:04 +01:00
i2c ALSA: i2c: Constify snd_kcontrol_new items 2020-01-03 09:24:24 +01:00
isa ALSA: emu8000: Fix the cast to __user pointer 2020-02-10 08:26:38 +01:00
mips ALSA: sgio2audio: Remove usage of dropped hw_params/hw_free functions 2020-03-06 12:06:41 +01:00
oss
parisc sound updates for 5.6-rc1 2020-01-28 16:26:57 -08:00
pci Merge branch 'for-linus' into for-next 2020-03-09 19:50:18 +01:00
pcmcia ALSA: pdaudiocf: More constification 2020-01-05 16:15:13 +01:00
ppc ALSA: ppc: More constifications 2020-01-05 16:14:43 +01:00
sh ALSA: sh: Fix compile warning wrt const 2020-01-05 16:15:14 +01:00
soc ASoC: Fixes for v5.6 2020-03-07 07:24:36 +01:00
sparc ALSA: sparc: More constifications 2020-01-05 16:14:56 +01:00
spi ALSA: spi: More constification 2020-01-05 16:15:13 +01:00
synth ALSA: emux: More constifications 2020-01-05 16:14:46 +01:00
usb ALSA: usb-audio: Inform devices that need delayed registration 2020-03-26 10:49:08 +01:00
x86 sound updates for 5.6-rc1 2020-01-28 16:26:57 -08:00
xen ALSA: xen: Drop superfluous ioctl PCM ops 2019-12-11 07:25:35 +01:00
ac97_bus.c ALSA: ac97: Treat snd_ac97_bus_ops as const 2020-01-03 09:24:08 +01:00
Kconfig
last.c
Makefile
sound_core.c