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#1 2026-04-07 12:04:50

dcqwlkkjd
Member
Registered: 2026-04-07
Posts: 3

HDMI Sound issue with USB-C Hub and alsa/pipewire/wireplumber

Hello,

I have an issue on my laptop where the sound from the HDMI port on a USB-c hub isn't played on the tv speakers.
I have made some investigation and here are the results.

kernel version

uname -a
Linux computer 6.18.21-1-lts #1 SMP PREEMPT_DYNAMIC Thu, 02 Apr 2026 15:44:36 +0000 x86_64 GNU/Linux

I have only one sink listed

pactl list short sinks
471     alsa_output.pci-0000_00_1f.3.hdmi-stereo        PipeWire        s32le 2ch 48000Hz       RUNNING

For alsa profile, I have the extra1,2,3 available but they also doesn't work  (every settings is greyed out in KDE sound settings and pavucontrol mark the profile as not plugged)
I can see on asound that the ELD negotiation for HDMI is successful, still I cannot hear sound.

cat /proc/asound/card0/eld\#2.16
monitor_present         1
eld_valid               1
codec_pin_nid           0xb
codec_dev_id            0x0
codec_cvt_nid           0x3
monitor_name            AAA
connection_type         DisplayPort
eld_version             [0x2] CEA-861D or below
edid_version            [0x3] CEA-861-B, C or D
manufacture_id          0x1863
product_id              0x0
port_id                 0x0
support_hdcp            0
support_ai              0
audio_sync_delay        0
speakers                [0x1] FL/FR
sad_count               1
sad0_coding_type        [0x1] LPCM
sad0_channels           2
sad0_rates              [0xe0] 32000 44100 48000
sad0_bits               [0x6] 16 20

On the error itself, I use to have the sound working for one day and after a screen off/screen on, it suddenly stopped working. The hub is working with a Windows computer, and another HDMI hub is working with my laptop.
I think it might be a mapping error between alsa/pipewire/wireplumber and the physical output but I don't know how to fix it.

Did it already happen to you ? Or do you have any insights on where to look please ?

Thank you !
PS:

When connecting the hub I get the following dmesg

[  +8,723541] usb 3-4: new high-speed USB device number 10 using xhci_hcd
[  +0,137487] usb 3-4: New USB device found, idVendor=05e3, idProduct=0610, bcdDevice= 6.63
[  +0,000005] usb 3-4: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[  +0,000001] usb 3-4: Product: USB2.1 Hub
[  +0,000001] usb 3-4: Manufacturer: GenesysLogic
[  +0,001323] hub 3-4:1.0: USB hub found
[  +0,000269] hub 3-4:1.0: 4 ports detected
[  +0,047857] usb 2-3: new SuperSpeed USB device number 7 using xhci_hcd
[  +0,023577] usb 2-3: New USB device found, idVendor=05e3, idProduct=0626, bcdDevice= 6.63
[  +0,000004] usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[  +0,000001] usb 2-3: Product: USB3.1 Hub
[  +0,000001] usb 2-3: Manufacturer: GenesysLogic
[  +0,001302] hub 2-3:1.0: USB hub found
[  +0,000804] hub 2-3:1.0: 4 ports detected
[  +0,277662] usb 2-3.3: new SuperSpeed USB device number 8 using xhci_hcd
[  +0,018880] usb 2-3.3: New USB device found, idVendor=0b95, idProduct=1790, bcdDevice= 2.00
[  +0,000005] usb 2-3.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  +0,000001] usb 2-3.3: Product: AX88179B
[  +0,000001] usb 2-3.3: Manufacturer: ASIX
[  +0,000001] usb 2-3.3: SerialNumber: 006C1FF770BFAA
[  +0,048744] cdc_ncm 2-3.3:2.0: MAC-Address: 6c:1f:f7:72:06:ee
[  +0,000006] cdc_ncm 2-3.3:2.0: setting rx_max = 16384
[  +0,000266] cdc_ncm 2-3.3:2.0: setting tx_max = 16384
[  +0,000391] cdc_ncm 2-3.3:2.0 eth0: register 'cdc_ncm' at usb-0000:00:0d.0-3.3, CDC NCM (NO ZLP), 6c:1f:f7:72:06:
ee
[  +0,008501] cdc_ncm 2-3.3:2.0 enp0s13f0u3u3c2: renamed from eth0
[  +0,822938] usb 3-4.2: new full-speed USB device number 11 using xhci_hcd
[  +0,106144] usb 3-4.2: New USB device found, idVendor=4037, idProduct=2804, bcdDevice= 1.10
[  +0,000004] usb 3-4.2: New USB device strings: Mfr=0, Product=1, SerialNumber=0
[  +0,000001] usb 3-4.2: Product: 2.4G Composite Devic
[  +0,006777] input: 2.4G Composite Devic as /devices/pci0000:00/0000:00:14.0/usb3/3-4/3-4.2/3-4.2:1.0/0003:4037:28
04.0009/input/input41
[  +0,130537] hid-generic 0003:4037:2804.0009: input,hidraw2: USB HID v1.10 Keyboard [2.4G Composite Devic] on usb-
0000:00:14.0-4.2/input0
[  +0,002511] input: 2.4G Composite Devic Mouse as /devices/pci0000:00/0000:00:14.0/usb3/3-4/3-4.2/3-4.2:1.1/0003:4
037:2804.000A/input/input42
[  +0,000088] input: 2.4G Composite Devic Consumer Control as /devices/pci0000:00/0000:00:14.0/usb3/3-4/3-4.2/3-4.2
:1.1/0003:4037:2804.000A/input/input43
[  +0,050707] input: 2.4G Composite Devic System Control as /devices/pci0000:00/0000:00:14.0/usb3/3-4/3-4.2/3-4.2:1
.1/0003:4037:2804.000A/input/input44
[  +0,000053] hid-generic 0003:4037:2804.000A: input,hidraw3: USB HID v1.10 Mouse [2.4G Composite Devic] on usb-000
0:00:14.0-4.2/input1

And I don't have more message when plugging in the HDMI separetly.

Update :
I have found this topic: https://bbs.archlinux.org/viewtopic.php?id=309588 and followed this article https://wiki.archlinux.org/title/PipeWi … sound_card and it seems that it creates two sinks but the HDMI one still doesn't work.

pactl list sinks short  
57      alsa_output.pci-0000_00_1f.3.analog-stereo      PipeWire        s32le 2ch 48000Hz       IDLE
58      alsa_output.pci-0000_00_1f.3.hdmi-stereo        PipeWire        s32le 2ch 48000Hz       RUNNING

I can also share the pwctl status

wpctl status                                              
PipeWire 'pipewire-0' [1.6.2, jojo@computer, cookie:951222469]
 └─ Clients:
        32. plasmashell                         [1.6.2, user@computer, pid:4621]
        33. xdg-desktop-portal                  [1.6.2, user@computer, pid:4380]
        34. pipewire                            [1.6.2, user@computer, pid:445947]
        35. libcanberra                         [1.6.2, user@computer, pid:4560]
        36.                                     [1.6.2, user@computer, pid:4621]
        37. WirePlumber                         [1.6.2, user@computer, pid:445946]
        38. libcanberra                         [1.6.2, user@computer, pid:4621]
        39.                                     [1.6.2, user@computer, pid:4560]
        40. Démon de KDEConnect                [1.6.2, user@computer, pid:4853]
        53. WirePlumber [export]                [1.6.2, user@computer, pid:445946]
        74. wpctl                               [1.6.2, user@computer, pid:447376]

Audio
 ├─ Devices:
 │      54. Audio interne                       [alsa]
 │  
 ├─ Sinks:
 │  *   58. Audio interne Stéréo analogique   [vol: 1.00]
 │      59. Audio interne Stéréo numérique (HDMI) [vol: 1.00]
 │  
 ├─ Sources:
 │  *   60. Audio interne Stéréo analogique   [vol: 1.00 MUTED]
 │  
 ├─ Filters:
 │  
 └─ Streams:

Video
 ├─ Devices:
 │      63. Integrated_Webcam_HD                [v4l2]
 │      64. Integrated_Webcam_HD                [v4l2]
 │      69. Integrated_Webcam_HD: Integrate     [libcamera]
 │  
 ├─ Sinks:
 │  
 ├─ Sources:
 │  *   72. Integrated_Webcam_HD (V4L2)        
 │  
 ├─ Filters:
 │  
 └─ Streams:

Settings
 └─ Default Configured Devices:
         0. Audio/Sink    bluez_output.7C_96_D2_E8_8C_41.1

Last edited by dcqwlkkjd (2026-04-08 15:15:27)

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#2 2026-04-10 13:58:34

dcqwlkkjd
Member
Registered: 2026-04-07
Posts: 3

Re: HDMI Sound issue with USB-C Hub and alsa/pipewire/wireplumber

From my last investigation what I can say is:

  • the hub works with other computers

  • I can play sound with another hub via HDMI and the same configuration on the same computer (still the sound is only mono)

So I think it is an issue between the new hub and the audio stack:

What do you think ?

Last edited by dcqwlkkjd (2026-04-10 14:01:11)

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