[alsa-devel] [PATCH v3 4/4] ALSA: hda - Add DP-MST support for NVIDIA codecs

[Martin Regner]

Hi Takashi,

thanks for your reply. I tried that with

cat /proc/asound/card0/codec#0

but that doesn't help. I'm digging me through the kernel config right 
now. May have to change something else.

I simply could create a patch on my gentoo system switching from 
patch_nvhdmi to patch_nvhdmi_legacy for every new kernel, but that won't 
work forever.

If you have other thinks i could try i'd appreciate to hear them.

kind regards
Martin

On 02.02.20 09:37, Takashi Iwai wrote:
> On Sat, 01 Feb 2020 16:28:08 +0100,
> Martin Regner wrote:
>> Hi there,
>>
>> since i updated to kernel 5.5 i have no sound over hdmi anymore (GeForce RTX
>> 2070).
>>
>> With the previous kernel 5.4.14 everything is fine.
>>
>> Although i got sound with speaker-test -D hdmi:CARD=NVidia,DEV=2 -c 2 -r
>> 44100, pavucontrol shows all hdmi sound devices as unplugged.
>>
>> I bisected it down to this commit (5398e94fb753d022301825ebfa5f7cf8a660d8eb)
>> and changed the line
>>
>> HDA_CODEC_ENTRY(0x10de0093, "GPU 93 HDMI/DP",  patch_nvhdmi)
>>
>> to
>>
>> HDA_CODEC_ENTRY(0x10de0093, "GPU 93 HDMI/DP",  patch_nvhdmi_legacy)
>>
>> Now it's working again. I'm not sure if this is a problem with pulseaudio or
>> if the RTX 2070 does not support the mentioned codec.
> The runtime PM turns off the link, so the hotplug notification won't
> be delivered as default.  Please try reading the corresponding proc
> file, /proc/asound/card*/codec* file.  This may power up the codec and
> trigger the hotplug detection if that's the cause.
>
>
> Takashi