linux/sound
Christos Skevis 4a63e68a29 ALSA: usb-audio: Fix microphone sound on Nexigo webcam.
I own an external usb Webcam, model NexiGo N930AF, which had low mic volume and
inconsistent sound quality. Video works as expected.

(snip)
[  +0.047857] usb 5-1: new high-speed USB device number 2 using xhci_hcd
[  +0.003406] usb 5-1: New USB device found, idVendor=1bcf, idProduct=2283, bcdDevice=12.17
[  +0.000007] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0.000004] usb 5-1: Product: NexiGo N930AF FHD Webcam
[  +0.000003] usb 5-1: Manufacturer: SHENZHEN AONI ELECTRONIC CO., LTD
[  +0.000004] usb 5-1: SerialNumber: 20201217011
[  +0.003900] usb 5-1: Found UVC 1.00 device NexiGo N930AF FHD Webcam (1bcf:2283)
[  +0.025726] usb 5-1: 3:1: cannot get usb sound sample rate freq at ep 0x86
[  +0.071482] usb 5-1: 3:2: cannot get usb sound sample rate freq at ep 0x86
[  +0.004679] usb 5-1: 3:3: cannot get usb sound sample rate freq at ep 0x86
[  +0.051607] usb 5-1: Warning! Unlikely big volume range (=4096), cval->res is probably wrong.
[  +0.000005] usb 5-1: [7] 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 :

(snip)
Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       3
      bNumEndpoints           1
      bInterfaceClass         1 Audio
      bInterfaceSubClass      2 Streaming
      bInterfaceProtocol      0
      iInterface              0
      AudioStreaming Interface Descriptor:
        bLength                 7
        bDescriptorType        36
        bDescriptorSubtype      1 (AS_GENERAL)
        bTerminalLink           8
        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]        44100
      Endpoint Descriptor:
        bLength                 9
        bDescriptorType         5
        bEndpointAddress     0x86  EP 6 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x005c  1x 92 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)

Based on the usb data about manufacturer, SPCA2281B3 is the most likely controller IC
Manufacturer does not provide link for datasheet nor detailed specs.
No way to confirm if the firmware supports any other way of getting the sample rate.

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

(snip)
[  +0.045764] usb 5-1: new high-speed USB device number 2 using xhci_hcd
[  +0.106290] usb 5-1: New USB device found, idVendor=1bcf, idProduct=2283, bcdDevice=12.17
[  +0.000006] usb 5-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0.000004] usb 5-1: Product: NexiGo N930AF FHD Webcam
[  +0.000003] usb 5-1: Manufacturer: SHENZHEN AONI ELECTRONIC CO., LTD
[  +0.000004] usb 5-1: SerialNumber: 20201217011
[  +0.043700] usb 5-1: set resolution quirk: cval->res = 16
[  +0.002585] usb 5-1: Found UVC 1.00 device NexiGo N930AF FHD Webcam (1bcf:2283)

Signed-off-by: Christos Skevis <xristos.thes@gmail.com>
Link: https://lore.kernel.org/r/20231006155330.399393-1-xristos.thes@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-10-09 08:20:00 +02:00
..
ac97 ALSA: ac97: set variables dev_attr_vendor_id to static 2023-08-02 09:27:39 +02:00
aoa ALSA: aoa: Fix typos in PCM fix patch 2023-08-18 09:09:39 +02:00
arm ARM: pxa: fix missing-prototypes warnings 2023-05-26 13:33:05 +02:00
atmel ALSA: Explicitly include correct DT includes 2023-07-16 14:50:56 +02:00
core ALSA: rawmidi: Fix NULL dereference at proc read 2023-09-16 08:08:05 +02:00
drivers ASoC: Updates for v6.6 2023-08-28 16:13:03 +02:00
firewire ALSA: firewire: Fix -Wformat-truncation warning for MIDI stream names 2023-09-15 13:22:06 +02:00
hda ALSA: hda: intel-sdw-acpi: Use u8 type for link index 2023-09-13 09:43:10 +02:00
i2c
isa ALSA: cs4231: Fix -Wformat-truncation warning for longname string 2023-09-15 13:23:01 +02:00
mips
oss
parisc
pci ALSA: hda/realtek: Change model for Intel RVP board 2023-10-06 11:11:18 +02:00
pcmcia ALSA: add HAS_IOPORT dependencies 2023-05-22 16:43:47 +02:00
ppc ALSA: Explicitly include correct DT includes 2023-07-16 14:50:56 +02:00
sh ALSA: sh: Convert to generic PCM copy ops 2023-08-18 12:18:24 +02:00
soc ASoC: amd: yc: Fix non-functional mic on Lenovo 82YM 2023-10-02 16:17:44 +01:00
sparc ALSA: Explicitly include correct DT includes 2023-07-16 14:50:56 +02:00
spi
synth ALSA: emu10k1: fix synthesizer pitch for E-MU cards at 44.1 kHz 2023-06-13 07:42:08 +02:00
usb ALSA: usb-audio: Fix microphone sound on Nexigo webcam. 2023-10-09 08:20:00 +02:00
virtio
x86
xen ALSA: xen: Fix -Wformat-truncation warning 2023-09-15 13:21:35 +02:00
ac97_bus.c
Kconfig This pull request contains the following changes for UML: 2023-09-04 11:32:21 -07:00
last.c
Makefile
sound_core.c sound: make all 'class' structures const 2023-06-21 07:29:10 +02:00