hdmi - no video output when there is no audio

[F.V.]

I've read a lot of hdmi related threads but no one seems to have the same problem I'm dealing with.

I have an LG S510 laptop (GeForce 9600M GT graphics card), and I'm connecting it to a LG TV screen through HDMI.
I'm running ubuntu 10.10 with nvidia proprietary driver version 260.19.06, and alsa driver version 1.0.23.

After I enable the external TV screen (through the nvidia gui or with fn+F7), and select HDMI output in sound preferences, everything works perfectly as long as I'm playing any sound (banshee, mplayer, etc). If I either stop playing sound or disable hdmi out in sound preferences, the video stops as well, and my TV screen displays a "no signal" message.

This annoying problem prevents me of using the external screen without audio.

I haven't read about this problem yet, so I'm guessing that this is the result of some messed up configuration.

My /etc/modprobe.d/alsa-base.conf:

# autoloader aliases
install sound-slot-0 /sbin/modprobe snd-card-0
install sound-slot-1 /sbin/modprobe snd-card-1
install sound-slot-2 /sbin/modprobe snd-card-2
install sound-slot-3 /sbin/modprobe snd-card-3
install sound-slot-4 /sbin/modprobe snd-card-4
install sound-slot-5 /sbin/modprobe snd-card-5
install sound-slot-6 /sbin/modprobe snd-card-6
install sound-slot-7 /sbin/modprobe snd-card-7

# Cause optional modules to be loaded above generic modules
install  snd /sbin/modprobe --ignore-install snd $CMDLINE_OPTS && {  /sbin/modprobe --quiet --use-blacklist snd-ioctl32 ; /sbin/modprobe  --quiet --use-blacklist snd-seq ; }
#
# Workaround at bug #499695 (reverted in Ubuntu see LP #319505)
install  snd-pcm /sbin/modprobe --ignore-install snd-pcm $CMDLINE_OPTS  && { /sbin/modprobe --quiet --use-blacklist snd-pcm-oss ; : ; }
install  snd-mixer /sbin/modprobe --ignore-install snd-mixer $CMDLINE_OPTS  && { /sbin/modprobe --quiet --use-blacklist snd-mixer-oss ; : ; }
install  snd-seq /sbin/modprobe --ignore-install snd-seq $CMDLINE_OPTS  && { /sbin/modprobe --quiet --use-blacklist snd-seq-midi ;  /sbin/modprobe --quiet --use-blacklist snd-seq-oss ; : ; }
#
install  snd-rawmidi /sbin/modprobe --ignore-install snd-rawmidi $CMDLINE_OPTS  && { /sbin/modprobe --quiet --use-blacklist snd-seq-midi ; : ; }
# Cause optional modules to be loaded above sound card driver modules
install  snd-emu10k1 /sbin/modprobe --ignore-install snd-emu10k1 $CMDLINE_OPTS  && { /sbin/modprobe --quiet --use-blacklist snd-emu10k1-synth ; }
install  snd-via82xx /sbin/modprobe --ignore-install snd-via82xx $CMDLINE_OPTS  && { /sbin/modprobe --quiet --use-blacklist snd-seq ; }

# Load saa7134-alsa instead of saa7134 (which gets dragged in by it anyway)
install  saa7134 /sbin/modprobe --ignore-install saa7134 $CMDLINE_OPTS  && { /sbin/modprobe --quiet --use-blacklist saa7134-alsa ; : ; }
# Prevent abnormal drivers from grabbing index 0
options bt87x index=-2
options cx88_alsa index=-2
options saa7134-alsa index=-2
options snd-atiixp-modem index=-2
options snd-intel8x0m index=-2
options snd-via82xx-modem index=-2
options snd-usb-audio index=-2
options snd-usb-caiaq index=-2
options snd-usb-ua101 index=-2
options snd-usb-us122l index=-2
options snd-usb-usx2y index=-2
# Ubuntu #62691, enable MPU for snd-cmipci
options snd-cmipci mpu_port=0x330 fm_port=0x388
# Keep snd-pcsp from being loaded as first soundcard
options snd-pcsp index=-2
# Keep snd-usb-audio from beeing loaded as first soundcard
options snd-usb-audio index=-2

My /etc/X11/xorg.conf

# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# Note that some configuration settings that could be done previously
# in this file, now are automatically configured by the server and settings
# here are ignored.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
#   sudo dpkg-reconfigure -phigh xserver-xorg

Section "Monitor"
    Identifier    "Configured Monitor"
EndSection

Section "Screen"
    Identifier    "Default Screen"
    Monitor        "Configured Monitor"
    Device        "Configured Video Device"
    DefaultDepth    24
EndSection

Section "Module"
    Load    "glx"
EndSection

Section "Device"
    Identifier    "Configured Video Device"
    Driver    "nvidia"
    Option    "NoLogo"    "True"
EndSection

Where should I be looking at?

[0kumy0]

Hi,

We have the same problem here : http://nvnews.net/vbulletin/showthread.php?p=2390795

Did you manage to get it working now ?

[F.V.]

Thanks for replying. I'm still stuck with this problem.

From your link I can see that the problem is specific with LG TV screens. I will try the suggested workaround, since I prefer having no audio through HDMI than intermittent video.