From a39978ed6df1bc0b29bc6820e8878b49e428426b Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 29 Jul 2021 09:44:04 +0200 Subject: ALSA: doc: Add the description of quirk_flags option for snd-usb-audio Just briefly described about the new option. Link: https://lore.kernel.org/r/20210729074404.19728-6-tiwai@suse.de Signed-off-by: Takashi Iwai --- Documentation/sound/alsa-configuration.rst | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) (limited to 'Documentation/sound/alsa-configuration.rst') diff --git a/Documentation/sound/alsa-configuration.rst b/Documentation/sound/alsa-configuration.rst index b36af65a08ed..f148b58502c0 100644 --- a/Documentation/sound/alsa-configuration.rst +++ b/Documentation/sound/alsa-configuration.rst @@ -2252,6 +2252,25 @@ delayed_register The driver prints a message like "Found post-registration device assignment: 1234abcd:04" for such a device, so that user can notice the need. +quirk_flags + Contains the bit flags for various device specific workarounds. + Applied to the corresponding card index. + * bit 0: Skip reading sample rate for devices + * bit 1: Create Media Controller API entries + * bit 2: Allow alignment on audio sub-slot at transfer + * bit 3: Add length specifier to transfers + * bit 4: Start playback stream at first in implement feedback mode + * bit 5: Skip clock selector setup + * bit 6: Ignore errors from clock source search + * bit 7: Indicates ITF-USB DSD based DACs + * bit 8: Add a delay of 20ms at each control message handling + * bit 9: Add a delay of 1-2ms at each control message handling + * bit 10: Add a delay of 5-6ms at each control message handling + * bit 11: Add a delay of 50ms at each interface setup + * bit 12: Perform sample rate validations at probe + * bit 13: Disable runtime PM autosuspend + * bit 14: Ignore errors for mixer access + * bit 15: Support generic DSD raw U32_BE format This module supports multiple devices, autoprobe and hotplugging. @@ -2261,11 +2280,14 @@ check. NB: ``ignore_ctl_error=1`` may help when you get an error at accessing the mixer element such as URB error -22. This happens on some -buggy USB device or the controller. +buggy USB device or the controller. This workaround corresponds to +the ``quirk_flags`` bit 14, too. -NB: quirk_alias option is provided only for testing / development. +NB: ``quirk_alias`` option is provided only for testing / development. If you want to have a proper support, contact to upstream for adding the matching quirk in the driver code statically. +Ditto for ``quirk_flags``. If a device is known to require specific +workarounds, please report to the upstream. Module snd-usb-caiaq -------------------- -- cgit v1.2.3