Fails to enable: Not multifunction, no audio

[skligys]

Dell Precision 5520 with Quadro M1200 4GB. In case it is relevant, I am using mvidia-xrun on Arch lInux (https://wiki.archlinux.org/index.php/nvidia-xrun).

Enabling nvhda fails here:

nvhda/nvhda.c

Line 150 in 9e9bba5

if (!(hdr_type & 0x80))

yet in my limited understanding the multifunction bit is set (see 0x80 at offset 0x0E at the very bottom).

$ dmesg
[Jan 2 10:53] bbswitch: enabling discrete graphics
[  +0.325967] nvidia-nvlink: Nvlink Core is being initialized, major device number 234
[  +0.100344] NVRM: loading NVIDIA UNIX x86_64 Kernel Module  415.25  Wed Dec 12 10:22:08 CST 2018 (using threaded interrupts)
[  +0.013972] nvidia-modeset: Loading NVIDIA Kernel Mode Setting Driver for UNIX platforms  415.25  Wed Dec 12 10:02:42 CST 2018
[  +0.002218] [drm] [nvidia-drm] [GPU ID 0x00000100] Loading driver
[  +0.000002] [drm] Initialized nvidia-drm 0.0.0 20160202 for 0000:01:00.0 on minor 1
[  +0.010524] nvhda: version 0.01
[  +0.000007] nvhda: Found nv VGA device 0000:01:00.0
[  +0.000006] nvhda: enabling audio
[  +0.000001] nvhda: Not multifunction, no audio
[  +0.000004] nvhda: No audio device found, unsetting config bit.
[  +0.000001] nvhda: Succesfully loaded. Audio 0000:01:00.0 is off

$ lspci
...
01:00.0 3D controller: NVIDIA Corporation GM107GLM [Quadro M1200 Mobile] (rev a2)
...

$ sudo lspci -H1
...
01:00.0 3D controller: NVIDIA Corporation GM107GLM [Quadro M1200 Mobile] (rev a2)
01:00.1 Audio device: NVIDIA Corporation Device 0fbc (rev a1)
...

$ sudo lspci -d 10de:* -xxx
01:00.0 3D controller: NVIDIA Corporation GM107GLM [Quadro M1200 Mobile] (rev a2)
00: de 10 b6 13 07 00 10 00 a2 00 02 03 00 00 80 00
10: 00 00 00 ec 0c 00 00 c0 00 00 00 00 0c 00 00 d0
20: 00 00 00 00 01 e0 00 00 00 00 00 00 28 10 bf 07
30: 00 00 00 00 60 00 00 00 00 00 00 00 0b 01 00 00
40: 28 10 bf 07 00 00 00 00 00 00 00 00 00 00 00 00
50: 00 00 00 00 01 00 00 00 ce d6 23 00 00 00 00 00
60: 01 68 03 00 08 00 00 00 05 78 81 00 78 05 e0 fe
70: 00 00 00 00 00 00 00 00 10 00 02 00 e1 8d 2c 01
80: 30 21 00 00 03 bd 47 00 40 01 01 11 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 13 08 04 00
a0: 00 04 00 00 0e 00 00 00 03 00 1f 00 00 00 00 00
b0: 00 00 00 00 09 00 14 01 00 00 10 80 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

[hhfeuer]

Unfortunately, that's a misbehaviour of the kernel, depending on kernel version and maybe also on chipset and when it's enabled. The module asks the kernel to re-read the header type and the kernel reports 0x00 while it's really 0x80. Nothing I can do about it, sorry. You can only try a different kernel version or see if you can enable it later, maybe after display-manager start.

[skligys]

Thanks for taking a look. Do you think some delay would help before querying PCI header type back? I could easily try adding that.

[hhfeuer]

I think I tried that before to no avail but you'll never know. Maybe also reading the config byte twice helps, idk.

[skligys]

Ok, tried with msleep(100) before reading, did not help. However as you suggested starting X11 and then loading nvhda did help, it loaded fine!

Now the next problem is snd_hda_intel immediately saying: no codecs found! Any ideas on that?

[ +32.821851] nvhda: version 0.01
[  +0.000007] nvhda: Found nv VGA device 0000:01:00.0
[  +0.000006] nvhda: enabling audio
[  +0.000014] pci 0000:01:00.1: [10de:0fbc] type 00 class 0x040300
[  +0.000014] pci 0000:01:00.1: reg 0x10: [mem 0x00000000-0x00003fff]
[  +0.000028] pci 0000:01:00.1: Max Payload Size set to 256 (was 128, max 256)
[  +0.000102] nvhda: Audio found, adding
[  +0.000004] pci 0000:01:00.1: BAR 0: assigned [mem 0xed080000-0xed083fff]
[  +0.000012] pci 0000:01:00.1: Linked as a consumer to 0000:01:00.0
[  +0.000037] snd_hda_intel 0000:01:00.1: enabling device (0000 -> 0002)
[  +0.000084] snd_hda_intel 0000:01:00.1: Disabling MSI
[  +0.000018] snd_hda_intel 0000:01:00.1: Handle vga_switcheroo audio client
[  +0.000021] nvhda: Found nv audio device 0000:01:00.1
[  +0.000001] nvhda: Succesfully loaded. Audio 0000:01:00.0 is on
[  +0.003473] snd_hda_intel 0000:01:00.1: no codecs found!

[hhfeuer]

"no codecs found!" doesn't look good, never seen that before. Either a hardware failure or something is wrong with the snd_hda_intel module or its codecs. The codec module should be snd_hda_codec_hdmi

[skligys]

Thanks for help! Looks like this is out of nvhda driver's control now, closing the issue.