[Natty] Unreliable detection of snd-hda-intel with Conexant CX20549 codec

[marzojr]

Ever since the "up"grade to Ubuntu Natty, I have been having a host of problems with regards to audio. Foremost among them is the unreliable detection of sound related hardware during boot time. I have since done a clean install (keeping only home folder, but deleting all configuration other than Wine prefixes and virtual machines). The problem persists even now.

The symptoms of the problem are thus: at boot time, 3 things may happen: (1) the sound hardware (snd-hda-intel) will simply not be detected, (2) the sound hardware is detected but the codec isn't (snd-hda-codec-conexant) or (3) both are detected.

For cases (1) and (2), no sound is possible. Usually, but not always, I can get sound back by booting into a Lucid Live CD then booting back into Natty. For case (3), sound works, but is likely to stop working after a period of inactivity or with certain applications (Flash with Firefox, and Wine, are both reliable "killers" of audio); after audio stops working, I can get it back if I kill all programs that were using audio and run the following script:
echo "autospawn=no" > ~/.pulse/client.conf
pulseaudio -k
killall -q pulseaudio
sudo alsa force-reload
echo "autospawn=yes" > ~/.pulse/client.conf
pulseaudio -D

Sometimes, though, the above script will give the same results as case (2) above, which leads me to believe the issues are related. I have added the following lines to /etc/modprobe.d/alsa-base.conf (much as I needed to since Karmic):

Top:
alias snd-card-0 snd-hda-intel
alias sound-slot-0 snd-hda-intel
install snd-hda-intel /sbin/modprobe --ignore-install snd-hda-intel $CMDLINE_OPTS

End:
options snd-hda-intel index=-2 power_save=0 power_save_controller=N

At the moment, I have been able to get only case (1) working; the output of alsa-info.sh under these circumstances is here: http://www.alsa-project.org/db/?f=f157afd6ad28a41962b9058b164b3bdbd0dbf9be

Yesterday, I was able to get sound fully working; under those circumstances, alsa-info.sh returns this: http://www.alsa-project.org/db/?f=28ff7b24dba70a86acc5e8ae6d2dd5ef3bf1220b

The difference between cases (2) and (3) is that the Conexant codec is not found; the hardware is found, but I only have a "Dummy output" available for selection. kern.log confirms this: when I run the script I gave above, the following lines are printed in case (2):
[112070.826937] HDA Intel 0000:00:07.0: PCI INT A -> Link[LAZA] -> GSI 21 (level, low) -> IRQ 21
[112070.826942] hda_intel: Disable MSI for Nvidia chipset
[112070.827006] HDA Intel 0000:00:07.0: setting latency timer to 64
[112070.900039] hda-intel: no codecs found!
[112070.900099] HDA Intel 0000:00:07.0: PCI INT A disabled

But the following lines are printed in case (3):
[ 5.858654] HDA Intel 0000:00:07.0: PCI INT A -> Link[LAZA] -> GSI 21 (level, low) -> IRQ 21
[ 5.858657] hda_intel: Disable MSI for Nvidia chipset
[ 5.858717] HDA Intel 0000:00:07.0: setting latency timer to 64

If there is any further information I can give to help solve this problem, please ask.

[Luke Yelavich (themuso)]

I have an idea what might be going on, but I need you to try something for me.

Open the file /lib/udev/rules.d/90-pulseaudio.rules as root in an editor, and remove the following line:

ATTRS{vendor}=="0x10de", ENV{PULSE_PROFILE_SET}="nvidia.conf"

Save changes, then log out or reboot. If this clears up detection of your hardware, then it seems that a fix that was added for other users who have an NVIDIA hda device needs to be made somewhat more fine graned. The NVIDIA code we have there was for users who had NVIDIA devices with realtek codecs. It seems my colleague who made that fix was unaware of NVIDIA devices with Conexant codecs.

If removing the above line does help, then we will set about fixing things such that your system is excluded from loading that configuratino file.

Thanks.

[marzojr (marzojr)]

As far as I can tell, it made no difference; but I cannot be certain it did nothing, as I haven't been able to get audio working for the past week or so (except for one instance). But correct if I am wrong, but isn't PulseAudio is a sound server with an Alsa (default in Ubuntu) backend, with backend being responsible for detecting and managing hardware?

Anyway: kudos, you gave me the first new thing to try since I begun scouring the web trying to get it to work.

I have a couple other symptoms that may or may not help:
1) the times when I got the card to be detected (but not work) during boot, there are now two entries in boot.log instead of one:
 * Starting System V runlevel compatibility[ OK ]

 * Starting restore sound card(s') mixer state(s)[ OK ]

[...]
 * Starting deferred execution scheduler[ OK ]

 * Starting restore sound card(s') mixer state(s)[fail]

2) When the card fails to work on boot, there is no entry in /sys/devices/pci0000:00/ for the PCI address of the sound card (0000:00:07.0 in my case, as the attachments above show).

[marzojr (marzojr)]

After several months of fruitless attempts, the sound card started working on its own accord recently. I have been working around it with an external USB card, so I can't say when exactly it started working again -- particularly since I haven't rebooted very often lately, and have been using suspend/resume instead. But 2 days ago, after I was forced to reboot, it was back on. FYI, I am using natty-proposed, with and my kernel is version 2.6.38-11.50. It seems to have persisted working so far, but I still have some testing to do to be certain.

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 11.04 (natty) reached end-of-life on October 28, 2012.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test.

[Launchpad Janitor (janitor)]

[Expired for pulseaudio (Ubuntu) because there has been no activity for 60 days.]