Nvidia MCP51 HDA Audio problems

[hauger]

Hi.

I've spent about 4 days now reading through HOW TO's and various posts, but have come up empty handed every time. Hopefully the Kubuntu community can maybe help me a bit (or at least offer sympathies).

I'm trying to run 7.10 on my HP Pavilion dv2404ca laptop. The sound worked for the first couple runs, but stopped and now won't work. Anyways, here's what I have so far:

Installed MP3 support and played a bunch in Amarok. Everything seems normal, visualization is running nicely. This makes me believe that Amarok, as far as it's concerned, is talking to a working sound system.

Alsamixer run from the shell shows all settings normal (not muted, all turned way up). Same with amixer. Kmixer also shows everything on and running (it Identifies the sound system as HDA Nvidia).

Tried running sound programs from Root. No sound there either.

Output of lspci -v:

00:10.1 Audio device: nVidia Corporation MCP51 High Definition Audio (rev a2)
Subsystem: Hewlett-Packard Company Unknown device 30b5
Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 17
Memory at c0000000 (32-bit, non-prefetchable) [size=16K]
Capabilities: <access denied>

Output from lsmod | grep snd:

snd_hda_intel 263712 2
snd_pcm_oss 44672 0
snd_mixer_oss 17664 1 snd_pcm_oss
snd_pcm 80388 2 snd_hda_intel,snd_pcm_oss
snd_seq_dummy 4740 0
snd_seq_oss 33152 0
snd_seq_midi 9600 0
snd_rawmidi 25728 1 snd_seq_midi
snd_seq_midi_event 8448 2 snd_seq_oss,snd_seq_midi
snd_seq 53232 6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_mid i_event
snd_timer 24324 2 snd_pcm,snd_seq
snd_seq_device 9228 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi ,snd_seq
snd 54660 13 snd_hda_intel,snd_pcm_oss,snd_mixer_oss,snd_pcm,sn d_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_de vice
soundcore 8800 1 snd
snd_page_alloc 11400 2 snd_hda_intel,snd_pcm


Output from aplay --list-devices:
card 0: NVidia [HDA NVidia], device 0: CONEXANT Analog [CONEXANT Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 1: Conexant Digital [Conexant Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0


I've seem posts talking about recompiling ALSA from source, but I'm hesitant to do so, since the sound system does sometimes (but not often at all) work, and I really don't want to mess things up worse than they are (a real possibility). So.....HELP...PLEASE.

Thanks,
Rob.

[hauger]

Re: Nvidia MCP51 HDA Audio problems

The mystery continues. Logged into Kubuntu today....and the sound works. I have no idea why, I haven't done a thing to the system. I am almost perfectly sure that were I to reboot I would loose sound again for another week or two.

Arrgg this gremlin in the system is annoying to say the least.

[PraysToPan]

Re: Nvidia MCP51 HDA Audio problems

Are you dual booting Windows on your laptop? There is an issue with the Linux sound driver where it doesn't seem able to reset the hardware after warm rebooting from Windows. Try a complete shutdown from Windows. With the system off, remove the power cord and boot Linux then plug the cord back in.

Jon

[hauger]

Re: Nvidia MCP51 HDA Audio problems

Funny you mention that. I do dual boot, and if I do a shutdown and reboot in the morning with the power cord unplugged (booting from the battery), the sound does seem to work. This has worked for the last two boots. I'm not ready to call it a "workaround" yet, but it is promising.

Very odd bug though.