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wangdicheng f7e3ac300e ALSA: usb-audio: Fix microphone sound on HD webcam.
commit 74dba24088 upstream.

I own an external usb Webcam, HD webcam, which had low mic volume and
inconsistent sound quality. Video works as expected.

(snip)
[   95.473820][ 1] [   T73] usb 5-2.2: new high-speed USB device number 7 using xhci_hcd
[   95.773974][ 1] [   T73] usb 5-2.2: New USB device found, idVendor=1bcf, idProduct=2281, bcdDevice= 0.05
[   95.783445][ 1] [   T73] usb 5-2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[   95.791872][ 1] [   T73] usb 5-2.2: Product: HD webcam
[   95.797001][ 1] [   T73] usb 5-2.2: Manufacturer: Sunplus IT Co
[   95.802996][ 1] [   T73] usb 5-2.2: SerialNumber: 20200513
[   96.092610][ 2] [ T3680] usb 5-2.2: Warning! Unlikely big volume range (=4096), cval->res is probably wrong.
[   96.102436][ 2] [ T3680] usb 5-2.2: [5] FU [Mic Capture Volume] ch = 1, val = 0/4096/1

Set up quirk cval->res to 16 for 256 levels,
Set GET_SAMPLE_RATE quirk flag to stop trying to get the sample rate.
Confirmed that happened anyway later due to the backoff mechanism,
After 3 failures.

All audio stream on device interfaces share the same values,
apart from wMaxPacketSize and tSamFreq :

      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       4
      bNumEndpoints           1
      bInterfaceClass         1 Audio

Interface Descriptor:
  bLength                 9
  bDescriptorType         4
  bInterfaceNumber        3
  bAlternateSetting       4
  bNumEndpoints           1
  bInterfaceClass         1 Audio
  bInterfaceSubClass      2 Streaming
  bInterfaceProtocol      0
  iInterface              0
  AudioStreaming Interface Descriptor:
    bLength                 7
    bDescriptorType        36
    bDescriptorSubtype      1 (AS_GENERAL)
    bTerminalLink           3
    bDelay                  1 frames
    wFormatTag         0x0001 PCM
  AudioStreaming Interface Descriptor:
    bLength                11
    bDescriptorType        36
    bDescriptorSubtype      2 (FORMAT_TYPE)
    bFormatType             1 (FORMAT_TYPE_I)
    bNrChannels             1
    bSubframeSize           2
    bBitResolution         16
    bSamFreqType            1 Discrete
    tSamFreq[ 0]        48000
  Endpoint Descriptor:
    bLength                 9
    bDescriptorType         5
    bEndpointAddress     0x86  EP 6 IN
    bmAttributes            5
      Transfer Type            Isochronous
      Synch Type               Asynchronous
      Usage Type               Data
    wMaxPacketSize     0x0064  1x 100 bytes
    bInterval               4
    bRefresh                0
    bSynchAddress           0
    AudioStreaming Endpoint Descriptor:
      bLength                 7
      bDescriptorType        37
      bDescriptorSubtype      1 (EP_GENERAL)
      bmAttributes         0x01
        Sampling Frequency
      bLockDelayUnits         0 Undefined
      wLockDelay         0x0000
(snip)

Testing patch provides consistent good sound recording quality and volume range.

(snip)
[   95.473820][ 1] [   T73] usb 5-2.2: new high-speed USB device number 7 using xhci_hcd
[   95.773974][ 1] [   T73] usb 5-2.2: New USB device found, idVendor=1bcf, idProduct=2281, bcdDevice= 0.05
[   95.783445][ 1] [   T73] usb 5-2.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[   95.791872][ 1] [   T73] usb 5-2.2: Product: HD webcam
[   95.797001][ 1] [   T73] usb 5-2.2: Manufacturer: Sunplus IT Co
[   95.802996][ 1] [   T73] usb 5-2.2: SerialNumber: 20200513
[   96.110630][ 3] [ T3680] usbcore: registered new interface driver snd-usb-audio
[   96.114329][ 7] [ T3677] usb 5-2.2: Found UVC 1.00 device HD webcam (1bcf:2281)
[   96.167555][ 7] [ T3677] usbcore: registered new interface driver uvcvideo

Signed-off-by: wangdicheng <wangdicheng@kylinos.cn>
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20240719020906.8078-1-wangdich9700@163.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-19 05:45:15 +02:00
arch KVM: VMX: Split out the non-virtualization part of vmx_interrupt_blocked() 2024-08-19 05:45:14 +02:00
block block: initialize integrity buffer to zero before writing it to media 2024-08-19 05:44:50 +02:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto crypto: aead,cipher - zeroize key buffer after use 2024-07-18 13:07:27 +02:00
Documentation dt-bindings: thermal: correct thermal zone node name limit 2024-08-19 05:45:10 +02:00
drivers media: uvcvideo: Fix integer overflow calculating timestamp 2024-08-19 05:45:14 +02:00
fs jbd2: make jbd2_journal_get_max_txn_bufs() internal 2024-08-19 05:45:14 +02:00
include jbd2: make jbd2_journal_get_max_txn_bufs() internal 2024-08-19 05:45:14 +02:00
init init/main.c: Fix potential static_command_line memory overflow 2024-04-27 17:05:28 +02:00
io_uring io_uring: tighten task exit cancellations 2024-08-19 05:45:14 +02:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:28:45 +01:00
kernel task_work: Introduce task_work_cancel() again 2024-08-19 05:45:13 +02:00
lib mlxsw: spectrum_acl_erp: Fix object nesting warning 2024-08-19 05:44:56 +02:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm: mmap_lock: replace get_memcg_path_buf() with on-stack buffer 2024-08-19 05:45:10 +02:00
net ipv6: take care of scope when choosing the src addr 2024-08-19 05:45:11 +02:00
samples Add gitignore file for samples/fanotify/ subdirectory 2024-07-27 10:46:16 +02:00
scripts kconfig: remove wrong expr_trans_bool() 2024-07-27 10:46:09 +02:00
security task_work: s/task_work_cancel()/task_work_cancel_func()/ 2024-08-19 05:45:13 +02:00
sound ALSA: usb-audio: Fix microphone sound on HD webcam. 2024-08-19 05:45:15 +02:00
tools selftests/landlock: Add cred_transfer test 2024-08-19 05:45:14 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-10 16:18:34 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS trace: Relocate event helper files 2024-04-10 16:19:24 +02:00
Makefile Linux 5.15.164 2024-07-27 10:46:18 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.