[optimus, reverse PRIME] no HDMI audio

Submitted by post+fdo@ralfj.de

Assigned to Nouveau Project

Link to original bug (#103896)

Description

I have a Lenovo P50 which contains an NVIDIA Quadro M2000M in reverse PRIME configuration: The HDMI port is connected to the NVidia card. While getting an image onto the HDMI port works just fine, there is no audio.

I asked about this on IRC, the logs are at https://people.freedesktop.org/~cbrill/dri-log/index.php?channel=nouveau&highlight_names=&date=2017-11-24#t-2034. The summary is that I tried running the following script (after stopping X):

rmmod nouveau
setpci -s 01:00.0 0x488.l=0x2000000:0x2000000
echo 1 > /sys/bus/pci/devices/0000:01:00.0/remove
#echo 1 > /sys/bus/pci/devices/0000:00:01.0/rescan
echo 1 > /sys/bus/pci/rescan
modprobe nouveau

But that did not help. I then started X again, and lspci still shows only

$ sudo lspci -nn -d 10de:
01:00.0 VGA compatible controller [0300]: NVIDIA Corporation GM107GLM [Quadro M2000M] [10de:13b0] (rev a2)