<div dir="ltr"><div>Dear PulseAudio experts,</div><div><br></div>I just setup Arch Linux on a new Dell Precision 5520 laptop and, because the
built-in "nose-cam" is positioned under the display, I am using a new
Logitech HD Pro Webcam C920. The camera on the C920 works flawlessly. However, the builtin microphone only worked occasionally, and recently stopped working altogether.<div><br></div><div>Basically, the sound settings
for Gnome, PulseAudio (pavucontrol), and ALSA (alsamixer) all show the microphone and allow me to
select it, unmute it, and adjust its settings, but it doesn't actually pick up any
sound. At first, if I physically unplugged and replugged the device, the
microphone would sometimes work until the next (re)boot. Now I can't get it to work at all. I've tried plugging the
camera into different USB ports on the laptop, docking station, and
monitor with no luck.</div><div><br></div><div>I Googled and found others
with similar issues, but haven't pinned down a solution yet. So I am coming right to the source. I'm not sure if this is a PulseAudio, ALSA, USB, or maybe a driver issue, but I thought you all might be able to point me in the right direction. Any help
would be much appreciated.<br></div><div><br></div><div>Below is some initial information about my configuration. Please let me now what else would be useful and I will post it as soon as possible. Thanks!</div><div><br></div><div>Brandon</div><div><br></div><div><pre class="gmail-vscroll"><code>$ uname -a
Linux servo 4.15.3-1-ARCH #1 SMP PREEMPT Mon Feb 12 23:01:17 UTC 2018 x86_64 GNU/Linux
$ lsusb
Bus 004 Device 004: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter
Bus 004 Device 003: ID 0424:5537 Standard Microsystems Corp.
Bus 004 Device 002: ID 0424:5807 Standard Microsystems Corp.
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 004: ID 0bda:4014 Realtek Semiconductor Corp.
Bus 003 Device 008: ID 04d8:0b2a Microchip Technology, Inc.
Bus 003 Device 007: ID 046d:c52b Logitech, Inc. Unifying Receiver
Bus 003 Device 009: ID 046d:082d Logitech, Inc. HD Pro Webcam C920
Bus 003 Device 005: ID 0d3d:0001 Tangtop Technology Co., Ltd HID Keyboard
Bus 003 Device 003: ID 0424:2137 Standard Microsystems Corp.
Bus 003 Device 002: ID 0424:2807 Standard Microsystems Corp.
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0c45:6713 Microdia
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ pactl list sources
Source #3
State: SUSPENDED
Name: alsa_output.pci-0000_00_1f.3.analog-stereo.monitor
Description: Monitor of Built-in Audio Analog Stereo
Driver: module-alsa-card.c
Sample Specification: s16le 2ch 44100Hz
Channel Map: front-left,front-right
Owner Module: 8
Mute: no
Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB
balance 0.00
Base Volume: 65536 / 100% / 0.00 dB
Monitor of Sink: alsa_output.pci-0000_00_1f.3.analog-stereo
Latency: 0 usec, configured 0 usec
Flags: DECIBEL_VOLUME LATENCY
Properties:
device.description = "Monitor of Built-in Audio Analog Stereo"
device.class = "monitor"
alsa.card = "1"
alsa.card_name = "HDA Intel PCH"
alsa.long_card_name = "HDA Intel PCH at 0xedd28000 irq 175"
alsa.driver_name = "snd_hda_intel"
device.bus_path = "pci-0000:00:1f.3"
sysfs.path = "/devices/pci0000:00/0000:00:1f.3/sound/card1"
device.bus = "pci"
<a href="http://device.vendor.id">device.vendor.id</a> = "8086"
<a href="http://device.vendor.name">device.vendor.name</a> = "Intel Corporation"
<a href="http://device.product.id">device.product.id</a> = "a171"
<a href="http://device.product.name">device.product.name</a> = "CM238 HD Audio Controller"
device.form_factor = "internal"
device.string = "1"
module-udev-detect.discovered = "1"
device.icon_name = "audio-card-pci"
Formats:
pcm
Source #4
State: SUSPENDED
Name: alsa_input.pci-0000_00_1f.3.analog-stereo
Description: Built-in Audio Analog Stereo
Driver: module-alsa-card.c
Sample Specification: s16le 2ch 44100Hz
Channel Map: front-left,front-right
Owner Module: 8
Mute: yes
Volume: front-left: 0 / 0% / -inf dB, front-right: 0 / 0% / -inf dB
balance 0.00
Base Volume: 6554 / 10% / -60.00 dB
Monitor of Sink: n/a
Latency: 0 usec, configured 0 usec
Flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL DECIBEL_VOLUME LATENCY
Properties:
alsa.resolution_bits = "16"
device.api = "alsa"
device.class = "sound"
alsa.class = "generic"
alsa.subclass = "generic-mix"
<a href="http://alsa.name">alsa.name</a> = "ALC3266 Analog"
<a href="http://alsa.id">alsa.id</a> = "ALC3266 Analog"
alsa.subdevice = "0"
alsa.subdevice_name = "subdevice #0"
alsa.device = "0"
alsa.card = "1"
alsa.card_name = "HDA Intel PCH"
alsa.long_card_name = "HDA Intel PCH at 0xedd28000 irq 175"
alsa.driver_name = "snd_hda_intel"
device.bus_path = "pci-0000:00:1f.3"
sysfs.path = "/devices/pci0000:00/0000:00:1f.3/sound/card1"
device.bus = "pci"
<a href="http://device.vendor.id">device.vendor.id</a> = "8086"
<a href="http://device.vendor.name">device.vendor.name</a> = "Intel Corporation"
<a href="http://device.product.id">device.product.id</a> = "a171"
<a href="http://device.product.name">device.product.name</a> = "CM238 HD Audio Controller"
device.form_factor = "internal"
device.string = "front:1"
device.buffering.buffer_size = "352800"
device.buffering.fragment_size = "176400"
device.access_mode = "mmap+timer"
<a href="http://device.profile.name">device.profile.name</a> = "analog-stereo"
device.profile.description = "Analog Stereo"
device.description = "Built-in Audio Analog Stereo"
alsa.mixer_name = "Realtek ALC3266"
alsa.components = "HDA:10ec0298,102807bf,00100103 HDA:8086280b,80860101,00100000"
module-udev-detect.discovered = "1"
device.icon_name = "audio-card-pci"
Ports:
analog-input-internal-mic: Internal Microphone (priority: 8900)
analog-input-headphone-mic: Microphone (priority: 8700, not available)
analog-input-headset-mic: Headset Microphone (priority: 8800, not available)
Active Port: analog-input-internal-mic
Formats:
pcm
Source #5
State: IDLE
Name: alsa_output.usb-Generic_USB_Audio_200901010001-00.analog-stereo-speaker.monitor
Description: Monitor of USB Audio Speaker
Driver: module-alsa-card.c
Sample Specification: s24le 2ch 48000Hz
Channel Map: front-left,front-right
Owner Module: 7
Mute: no
Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB
balance 0.00
Base Volume: 65536 / 100% / 0.00 dB
Monitor of Sink: alsa_output.usb-Generic_USB_Audio_200901010001-00.analog-stereo-speaker
Latency: 0 usec, configured 2000000 usec
Flags: DECIBEL_VOLUME LATENCY
Properties:
device.description = "Monitor of USB Audio Speaker"
device.class = "monitor"
alsa.card = "0"
alsa.card_name = "USB Audio"
alsa.long_card_name = "Generic USB Audio at usb-0000:0e:00.0-1.5, high speed"
alsa.driver_name = "snd_usb_audio"
device.bus_path = "pci-0000:0e:00.0-usb-0:1.5:1.0"
sysfs.path = "/devices/pci0000:00/0000:00:1d.6/0000:06:00.0/0000:07:01.0/0000:09:00.0/0000:0a:04.0/0000:0c:00.0/0000:0d:01.0/0000:0e:00.0/usb3/3-1/3-1.5/3-1.5:1.0/sound/card0"
<a href="http://udev.id">udev.id</a> = "usb-Generic_USB_Audio_200901010001-00"
device.bus = "usb"
<a href="http://device.vendor.id">device.vendor.id</a> = "0bda"
<a href="http://device.vendor.name">device.vendor.name</a> = "Realtek Semiconductor Corp."
<a href="http://device.product.id">device.product.id</a> = "4014"
<a href="http://device.product.name">device.product.name</a> = "USB Audio"
device.serial = "Generic_USB_Audio_200901010001"
device.string = "0"
module-udev-detect.discovered = "1"
device.icon_name = "audio-card-usb"
Formats:
pcm
Source #6
State: RUNNING
Name: alsa_input.usb-046d_HD_Pro_Webcam_C920_D3BFD79F-02.analog-stereo
Description: HD Pro Webcam C920 Analog Stereo
Driver: module-alsa-card.c
Sample Specification: s16le 2ch 32000Hz
Channel Map: front-left,front-right
Owner Module: 29
Mute: no
Volume: front-left: 64881 / 99% / -0.26 dB, front-right: 64881 / 99% / -0.26 dB
balance 0.00
Base Volume: 9619 / 15% / -50.00 dB
Monitor of Sink: n/a
Latency: 237 usec, configured 40000 usec
Flags: HARDWARE HW_MUTE_CTRL HW_VOLUME_CTRL DECIBEL_VOLUME LATENCY
Properties:
alsa.resolution_bits = "16"
device.api = "alsa"
device.class = "sound"
alsa.class = "generic"
alsa.subclass = "generic-mix"
<a href="http://alsa.name">alsa.name</a> = "USB Audio"
<a href="http://alsa.id">alsa.id</a> = "USB Audio"
alsa.subdevice = "0"
alsa.subdevice_name = "subdevice #0"
alsa.device = "0"
alsa.card = "2"
alsa.card_name = "HD Pro Webcam C920"
alsa.long_card_name = "HD Pro Webcam C920 at usb-0000:0e:00.0-1.1.2, high speed"
alsa.driver_name = "snd_usb_audio"
device.bus_path = "pci-0000:0e:00.0-usb-0:1.1.2:1.2"
sysfs.path = "/devices/pci0000:00/0000:00:1d.6/0000:06:00.0/0000:07:01.0/0000:09:00.0/0000:0a:04.0/0000:0c:00.0/0000:0d:01.0/0000:0e:00.0/usb3/3-1/3-1.1/3-1.1.2/3-1.1.2:1.2/sound/card2"
<a href="http://udev.id">udev.id</a> = "usb-046d_HD_Pro_Webcam_C920_D3BFD79F-02"
device.bus = "usb"
<a href="http://device.vendor.id">device.vendor.id</a> = "046d"
<a href="http://device.vendor.name">device.vendor.name</a> = "Logitech, Inc."
<a href="http://device.product.id">device.product.id</a> = "082d"
<a href="http://device.product.name">device.product.name</a> = "HD Pro Webcam C920"
device.serial = "046d_HD_Pro_Webcam_C920_D3BFD79F"
device.form_factor = "webcam"
device.string = "front:2"
device.buffering.buffer_size = "256000"
device.buffering.fragment_size = "128000"
device.access_mode = "mmap+timer"
<a href="http://device.profile.name">device.profile.name</a> = "analog-stereo"
device.profile.description = "Analog Stereo"
device.description = "HD Pro Webcam C920 Analog Stereo"
alsa.mixer_name = "USB Mixer"
alsa.components = "USB046d:082d"
module-udev-detect.discovered = "1"
device.icon_name = "camera-web-usb"
Ports:
analog-input-mic: Microphone (priority: 8700)
Active Port: analog-input-mic
Formats:
pcm</code></pre><br></div></div>