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authorTakashi Iwai <tiwai@suse.de>2021-07-29 09:44:04 +0200
committerTakashi Iwai <tiwai@suse.de>2021-08-02 09:06:08 +0200
commita39978ed6df1bc0b29bc6820e8878b49e428426b (patch)
tree46b1b6a4ef18bbe206c5c59c60f216db28a33201 /Documentation/sound
parent5b517854420b53541af09dc9e097e93673c9226f (diff)
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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 <tiwai@suse.de>
Diffstat (limited to 'Documentation/sound')
-rw-r--r--Documentation/sound/alsa-configuration.rst26
1 files changed, 24 insertions, 2 deletions
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
--------------------