From nobody Fri Oct 3 14:34:19 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1AA0B1E0E1F; Fri, 29 Aug 2025 08:46:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756457189; cv=none; b=Bm7Pe8eixP/wzL4vyNii3dRwp76NSb5bgtW6Rmrtg+1yZceBIcjuxUQWwwNHpPT9w0Xx5O0gbUzUGN6gX+Y6ylTzys9xmG+A5XDnJElxIFQCgKxEgU6/4ZISuSHLBE/PLun0nno8v2c783FmT6QydticnzPiIXLrDUXwriOvFME= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756457189; c=relaxed/simple; bh=DialTkaZ2UwEoPpeuNzfbQp3IDqYgtAn+UUymBTw6Io=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=QLrifNB62Z6PX6av6qt5mYGeq11a5ncxRaw91noa4JiH/M2Nbl3VXX0KNUwo3WQQ0sFbmSaG2QXC0BM80013R2pLJziTHIPF2Rcz9bcNWviPt2YqWRHnVBAXf0KKbNJ1qoARNNax6dhebGcaGFStV7IsShdnDB22WegbgMYDxwA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Urlg8agv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Urlg8agv" Received: by smtp.kernel.org (Postfix) with ESMTPS id A02D1C4CEF0; Fri, 29 Aug 2025 08:46:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756457188; bh=DialTkaZ2UwEoPpeuNzfbQp3IDqYgtAn+UUymBTw6Io=; h=From:Date:Subject:To:Cc:Reply-To:From; b=Urlg8agveP3FzvS8aPPcBa0pIrmxh5TS9xYk/WTKKR/MJvNSJbvsqrhp7ciuMsfBx /lyhPxVNe9nj41BlFbwGYy3JbB3rE9S2AuHMDDHk6vM6KHVDZ326ExkUhHahxxZkWu kZUV7bEMEgH6HQjqRECYFEK1BPoxWabLLJiPx7fq7HO0e0mJ4zba7vct4Bk8XaSnC6 7ARztJKyhCglBs5euuaoSps8SLs0x0i7PzE9RkkI0VNAW/jG+wtbeoxMd1SDXDTqYA j/v9qHDzngfiySRJN3okkEWQMY+vtSy6L0fflQkUmOeJVAetmI/UoQ+iFpqlPqo0C9 6d3e+xdAoCUPQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90CB4CA0FF0; Fri, 29 Aug 2025 08:46:28 +0000 (UTC) From: Cryolitia PukNgae via B4 Relay Date: Fri, 29 Aug 2025 16:46:06 +0800 Subject: [PATCH] ALSA: docs: Add documents for recently changes in snd-usb-audio Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250829-sound-doc-v1-1-e0110452b03d@uniontech.com> X-B4-Tracking: v=1; b=H4sIAM1osWgC/6tWKk4tykwtVrJSqFYqSi3LLM7MzwNyDHUUlJIzE vPSU3UzU4B8JSMDI1MDCyNL3eL80rwU3ZT8ZF1z42SzVFMTEwvLFEMloPqCotS0zAqwWdGxtbU AYedTW1sAAAA= X-Change-ID: 20250829-sound-doc-73c6e54489d1 To: Jaroslav Kysela , Takashi Iwai , Jonathan Corbet Cc: linux-sound@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, niecheng1@uniontech.com, zhanjun@uniontech.com, Cryolitia PukNgae X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1756457187; l=3763; i=cryolitia@uniontech.com; s=20250730; h=from:subject:message-id; bh=HE89odsIwYI1Vul0J0CIerepfkejArZ/qTv9Q4oEXbY=; b=K4pQlW5283gHmgF0tuapReYbIHgrysYjpS0ltdEVRBVl5YcdIkLPZNJiNbKub9gScdwYiODmH koJvJicRJ6jAAjgm5wFOaskFcTntv3F86uVw9M/5r+XCm+6sbPDOBHQ X-Developer-Key: i=cryolitia@uniontech.com; a=ed25519; pk=tZ+U+kQkT45GRGewbMSB4VPmvpD+KkHC/Wv3rMOn/PU= X-Endpoint-Received: by B4 Relay for cryolitia@uniontech.com/20250730 with auth_id=474 X-Original-From: Cryolitia PukNgae Reply-To: cryolitia@uniontech.com From: Cryolitia PukNgae Changed: - ignore_ctl_error - lowlatency - skip_validation - quirk_flags[19:24] Signed-off-by: Cryolitia PukNgae --- Documentation/sound/alsa-configuration.rst | 29 +++++++++++++++++++++++++-= --- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/Documentation/sound/alsa-configuration.rst b/Documentation/sou= nd/alsa-configuration.rst index a45174d165ebdeadd89de5f556483465c5f6e808..77fd70ac12975a271600ebd5426= 72a3afb443d39 100644 --- a/Documentation/sound/alsa-configuration.rst +++ b/Documentation/sound/alsa-configuration.rst @@ -2253,8 +2253,15 @@ device_setup Default: 0x0000=20 ignore_ctl_error Ignore any USB-controller regarding mixer interface (default: no) + ``ignore_ctl_error=3D1`` 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 =20 This module supports multiple devices, autoprobe and hotplugging. =20 @@ -2314,10 +2336,9 @@ NB: ``nrpacks`` parameter can be modified dynamicall= y via sysfs. Don't put the value over 20. Changing via sysfs has no sanity check. =20 -NB: ``ignore_ctl_error=3D1`` 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=3D1`` 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. =20 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, --=20 Cryolitia PukNgae