From: Cryolitia PukNgae via B4 Relay <devnull+cryolitia.uniontech.com@kernel.org>
To: Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
Jonathan Corbet <corbet@lwn.net>
Cc: linux-sound@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, niecheng1@uniontech.com,
zhanjun@uniontech.com,
Cryolitia PukNgae <cryolitia@uniontech.com>
Subject: [PATCH] ALSA: docs: Add documents for recently changes in snd-usb-audio
Date: Fri, 29 Aug 2025 16:46:06 +0800 [thread overview]
Message-ID: <20250829-sound-doc-v1-1-e0110452b03d@uniontech.com> (raw)
From: Cryolitia PukNgae <cryolitia@uniontech.com>
Changed:
- ignore_ctl_error
- lowlatency
- skip_validation
- quirk_flags[19:24]
Signed-off-by: Cryolitia PukNgae <cryolitia@uniontech.com>
---
Documentation/sound/alsa-configuration.rst | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)
diff --git a/Documentation/sound/alsa-configuration.rst b/Documentation/sound/alsa-configuration.rst
index a45174d165ebdeadd89de5f556483465c5f6e808..77fd70ac12975a271600ebd542672a3afb443d39 100644
--- a/Documentation/sound/alsa-configuration.rst
+++ b/Documentation/sound/alsa-configuration.rst
@@ -2253,8 +2253,15 @@ device_setup
Default: 0x0000
ignore_ctl_error
Ignore any USB-controller regarding mixer interface (default: no)
+ ``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. This workaround corresponds to
+ the ``quirk_flags`` bit 14, too.
autoclock
Enable auto-clock selection for UAC2 devices (default: yes)
+lowlatency
+ Enable low latency playback mode (default: yes).
+ Could disable it to switch back to the old mode if face a regression.
quirk_alias
Quirk alias list, pass strings like ``0123abcd:5678beef``, which
applies the existing quirk for the device 5678:beef to a new
@@ -2284,6 +2291,11 @@ 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.
+skip_validation
+ Skip unit descriptor validation (default: no).
+ The option is used to ignores the validation errors with the hexdump
+ of the unit descriptor instead of a driver probe error, so that we
+ can check its details.
quirk_flags
Contains the bit flags for various device specific workarounds.
Applied to the corresponding card index.
@@ -2307,6 +2319,16 @@ quirk_flags
* bit 16: Set up the interface at first like UAC1
* bit 17: Apply the generic implicit feedback sync mode
* bit 18: Don't apply implicit feedback sync mode
+ * bit 19: Don't closed interface during setting sample rate
+ * bit 20: Force an interface reset whenever stopping & restarting
+ a stream
+ * bit 21: Do not set PCM rate (frequency) when only one rate is
+ available for the given endpoint.
+ * bit 22: Set the fixed resolution 16 for Mic Capture Volume
+ * bit 23: Set the fixed resolution 384 for Mic Capture Volume
+ * bit 24: Set minimum volume control value as mute for devices
+ where the lowest playback value represents muted state instead
+ of minimum audible volume
This module supports multiple devices, autoprobe and hotplugging.
@@ -2314,10 +2336,9 @@ NB: ``nrpacks`` parameter can be modified dynamically via sysfs.
Don't put the value over 20. Changing via sysfs has no sanity
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. This workaround corresponds to
-the ``quirk_flags`` bit 14, too.
+NB: ``ignore_ctl_error=1`` just provides A quick way to work around the
+issues. If you have a buggy device that requires these quirks, please
+report it to the upstream.
NB: ``quirk_alias`` option is provided only for testing / development.
If you want to have a proper support, contact to upstream for
---
base-commit: 15be520ab00cfc9c59fa1623de6757f61ab42d8a
change-id: 20250829-sound-doc-73c6e54489d1
Best regards,
--
Cryolitia PukNgae <cryolitia@uniontech.com>
reply other threads:[~2025-08-29 8:46 UTC|newest]
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