I have an Alfawise X5, which has two sound devices installed, one is HDMI sound delivered by the Intel Atom X5-Z8350 processor (a system on a chip, Cherry Trail series), and a headphone jack that seems to be driven by a RealTek ALC5651 (at least that chip sits on the board no far from the audio jack and it's a 2 channel audio chip).
I found this post:
Sound stopped working after upgrading to Linux 5.4 (Intel HD Audio)
because of obvious similarities. Namely all I see on PulseAudio is one Dummy Output:
$ pacmd list-sinks
1 sink(s) available.
* index: 0
name: <auto_null>
driver: <module-null-sink.c>
flags: DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY
state: SUSPENDED
suspend cause: IDLE
priority: 1000
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
volume steps: 65537
muted: no
current latency: 0.00 ms
max request: 375 KiB
max rewind: 375 KiB
monitor source: 0
sample spec: s16le 2ch 48000Hz
channel map: front-left,front-right
Stereo
used by: 0
linked by: 0
configured latency: 0.00 ms; range is 0.50 .. 2000.00 ms
module: 13
properties:
device.description = "Dummy Output"
device.class = "abstract"
device.icon_name = "audio-card"
but ALSA seems to see the HDMI sound output:
$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Audio [Intel HDMI/DP LPE Audio], device 0: HdmiLpeAudio [Intel HDMI/DP LPE Audi]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Audio [Intel HDMI/DP LPE Audio], device 1: HdmiLpeAudio [Intel HDMI/DP LPE Audi]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: Audio [Intel HDMI/DP LPE Audio], device 2: HdmiLpeAudio [Intel HDMI/DP LPE Audi]
Subdevices: 1/1
Subdevice #0: subdevice #0
and the kernel appears to have trouble finding the RealTek ALC5651:
$ dmesg | grep -C1 -E 'ALSA|HDA|sof|HDMI|snd[_-]|sound|hda.codec|hda.intel'
[ 0.000000] Linux version 5.4.0-60-generic (buildd@lgw01-amd64-001) (gcc version 9.3.0 (Ubuntu 9.3.0-17ubuntu1~20.04)) #67-Ubuntu SMP Tue Jan 5 18:31:36 UTC 2021 (Ubuntu 5.4.0-60.67-generic 5.4.78)
[ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.4.0-60-generic root=UUID=fa5731bf-76e3-41c2-874d-3d13a4d1b21d ro quiet splash snd_hda_intel.dmic_detect=0 snd-intel-dspcfg.dsp_driver=1
[ 0.000000] KERNEL supported cpus:
--
[ 0.048313] Policy zone: DMA32
[ 0.048319] Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.4.0-60-generic root=UUID=fa5731bf-76e3-41c2-874d-3d13a4d1b21d ro quiet splash snd_hda_intel.dmic_detect=0 snd-intel-dspcfg.dsp_driver=1
[ 0.049834] Dentry cache hash table entries: 262144 (order: 9, 2097152 bytes, linear)
--
[ 0.185244] ACPI: Added _OSI(Linux-Dell-Video)
[ 0.185247] ACPI: Added _OSI(Linux-Lenovo-NV-HDMI-Audio)
[ 0.185250] ACPI: Added _OSI(Linux-HPI-Hybrid-Graphics)
--
[ 4.441136] raid6: using ssse3x2 recovery algorithm
[ 4.444645] xor: measuring software checksum speed
[ 4.481073] prefetch64-sse: 6851.000 MB/sec
--
[ 10.285999] proc_thermal 0000:00:0b.0: Creating sysfs group for PROC_THERMAL_PCI
[ 10.579113] input: Intel HDMI/DP LPE Audio HDMI/DP,pcm=0 as /devices/pci0000:00/0000:00:02.0/hdmi-lpe-audio/sound/card0/input15
[ 10.582098] input: Intel HDMI/DP LPE Audio HDMI/DP,pcm=1 as /devices/pci0000:00/0000:00:02.0/hdmi-lpe-audio/sound/card0/input16
[ 10.582567] input: Intel HDMI/DP LPE Audio HDMI/DP,pcm=2 as /devices/pci0000:00/0000:00:02.0/hdmi-lpe-audio/sound/card0/input17
[ 10.637553] intel_sst_acpi 808622A8:00: No matching machine driver found
--
[ 10.721085] Bluetooth: hci0: RTL: cfg_sz 64, total sz 24508
[ 10.810374] sof-audio-acpi 808622A8:00: warning: No matching ASoC machine driver found
[ 10.813937] sof-audio-acpi 808622A8:00: error: no matching ASoC machine driver found - aborting probe
[ 10.813948] sof-audio-acpi 808622A8:00: error: failed to get machine info -19
[ 10.813954] sof-audio-acpi 808622A8:00: error: sof_probe_work failed err: -19
from which you can see I've tried a couple of the commonly recommended kernel options for 5.4 when sound stops working (and some more to be honest, have tried a fair bit).
I ran alsa-info and it uploaded here:
http://alsa-project.org/db/?f=661875506cd4920a7b7c6086518220c3603de257
This puzzles me some I admit, as it's a RealTek sound chip, which strikes me (in my admitted naiveté) as a fairly strong industry standard not some odd sound chip, that Android and Windows 10 can see it, but my linux install cannot (Linux Mint 20, built on Ubuntu 20.04).
I have no need for the HDMI sound, though someone posted here they got it working by rolling back to a 4.12 kernel:
I don't want HDMI sound as it happens, I have no use for it, but I do want the headphone jack to work. And rolling back to long dated kernels seems odd, given I'd expect as kernels evolve that significant behaviour changes like losing sound on a RealTek and Intel chips are spotted and fixed ... and I understood that's what these kernel options oft discussed on-line achieve ... though I have yet to find some definitive doc on options etc.)
