The lspci command seems not find any audio devices.~$ lspci 00:00.0 Host bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series SoC Transaction Register (rev 0f)00:02.0 VGA compatible controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Graphics & Display (rev 0f)00:14.0 USB controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series USB xHCI (rev 0f)00:1a.0 Encryption controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Trusted Execution Engine (rev 0f)00:1f.0 ISA bridge: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Power Control Unit (rev 0f)and alsamixer is 100.Here is the infomation of the audio driver I got from windows driver package:<DriverName>Realtek I2S Audio Codec</DriverName><ClassName>MEDIA</ClassName><Inf>oem20.inf</Inf><HardwareIDs><HID>ACPI\VEN_10EC&DEV_5640 ACPI\10EC5640*10EC5640 ACPI\10EC5640 10EC5640</HID></HardwareIDs><OS>82</OS><FileName>Realtek I2S Audio Codec.zip</FileName></item><item><DriverName>Intel SST Audio Device (WDM)</DriverName><ClassName>MEDIA</ClassName><Inf>oem10.inf</Inf><HardwareIDs><HID>ACPI\VEN_8086&DEV_0F28&SUBSYS_80867270 ACPI\80860F28*80860F28 ACPI\80860F28 80860F28</HID></HardwareIDs><OS>82</OS><FileName>Intel SST Audio Device (WDM).zip</FileName></item><item>Following this post, here is some relevant output:~$ lsmod | grep sndsnd_soc_sst_byt_rt5640_mach    12524  0 snd_soc_rt5640         82914  0 snd_soc_rl6231         12442  1 snd_soc_rt5640snd_soc_core          147300  2 snd_soc_rt5640,snd_soc_sst_byt_rt5640_machsnd_compress           17197  1 snd_soc_coresnd_pcm                88662  2 snd_soc_rt5640,snd_soc_coresnd_timer              26614  1 snd_pcmsnd                    65244  4 snd_soc_core,snd_timer,snd_pcm,snd_compresssoundcore              13026  1 sndregmap_i2c             12783  1 snd_soc_rt5640snd_soc_sst_acpi       12559  0 i2c_core               46012  8 drm,i915,snd_soc_rt5640,i2c_hid,i2c_designware_platform,regmap_i2c,drm_kms_helper,i2c_algo_bit~$ cat /proc/asound/cards --- no soundcards ---~$ aplay -Ldefault    Playback/recording through the PulseAudio sound servernull    Discard all samples (playback) or generate zero samples (capture)pulse    PulseAudio Sound Server~$ groups |grep audiolm cdrom floppy audio dip video plugdev netdev scanner bluetooth lpadminedit dmesg outputthere are quite a few post on internet about the belowing issue, seems no one found a good answer... [    3.647103] byt-rt5640 byt-rt5640: ASoC: CPU DAI baytrail-pcm-audio not registered548 [    3.647132] platform byt-rt5640: Driver byt-rt5640 requests probe deferral   549 [    3.649476] usb 1-1.1: New USB device found, idVendor=1017, idProduct=1006   550 [    3.649484] usb 1-1.1: New USB device strings: Mfr=0, Product=0, SerialNumber=0551 [    3.649689] usb 1-1.1: ep 0x81 - rounding interval to 64 microframes, ep desc says 80 microframes552 [    3.649701] usb 1-1.1: ep 0x82 - rounding interval to 64 microframes, ep desc says 80 microframes553 [    3.652310] byt-rt5640 byt-rt5640: ASoC: CPU DAI baytrail-pcm-audio not registered554 [    3.652338] platform byt-rt5640: Driver byt-rt5640 requests probe deferral   555 [    3.653581] byt-rt5640 byt-rt5640: ASoC: CPU DAI baytrail-pcm-audio not registered
system mute of fresh install debian, can't find the audio devices
debian;audio