# HDMI audio fails if xorg restarts/display absent on boot

## jnthornh

I have a system with an NVIDIA GeForce 8300 running 2.6.36 (but this problem was present on 2.6.34 as well). I use the nvidia binary drivers. This is a mythtv frontend, which is hooked up to an HDMI switching receiver.

My problem is rather odd. I have HDMI audio working - with two caveats. One, the receiver must be on when the system boots, or HDMI audio will not work. Two, if I restart xorg, HDMI audio stops working. HDMI audio works if xorg starts on boot and is later stopped, but once xorg starts the second time HDMI audio stops working. The only resolution I have found at that point is to reboot.

I have run with this setup for some time now and it has not always been this way. At some point in the past, restarting xorg actually caused no problems at all; in fact, it would make HDMI audio work if the receiver was not on when the system booted.

I am assuming that there is something odd with my xorg config that causes this problem, but I can't find any documentation on what it might be. I would appreciate any help.

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## jnthornh

So, anybody have any thoughts?

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## Jaglover

You say Xorg, what do you mean by that. I'm running MythTV frontend as well, I have no WM or DE installed and it works fine, plain ALSA.

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## VoidMage

There's an interesting note here claiming that on some of the cards,

HDMI sound only works with video.

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## Jaglover

That's true, my nVidia ION does exactly that. When I installed the box first I couldn't get the sound with mplayer from CLI. After reading up I still couldn't see anything wrong. Then I tried with SMplayer and video and to my surprise I got sound.   :Rolling Eyes:  I didn't know though, if this is a feature of my TV set or graphics card.

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## jnthornh

 *Jaglover wrote:*   

> You say Xorg, what do you mean by that. I'm running MythTV frontend as well, I have no WM or DE installed and it works fine, plain ALSA.

 

Seems to be related to xorg itself; I have the problem regardless of what runs afterward. Currently I'm having gdm auto-login xfce, but I can see the same thing happen when I just run startx, kill it, start it back up. For sanity I tried another distribution (Arch) on the same hardware to see what would happen, and I got identical behavior.

I suspect this is an issue with something the nvidia proprietary drivers are doing, and it's a recent change, since it didn't always behave this way. For whatever reason the second time it negotiates display settings, sound disappears. I don't know of any way I can debug it beyond that, though. I may try some older binary drivers or noveau to see if the results are similar.

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## jnthornh

 *VoidMage wrote:*   

> There's an interesting note here claiming that on some of the cards,
> 
> HDMI sound only works with video.

 

My experience doesn't quite match that though, IIRC. Assuming that my TV and receiver are powered on and set to this input when the system first boots, what happens is:

- fresh boot, no xorg: sound works

- start xorg first time: sound still works

- stop xorg: sound still works

- start xorg again: stound stops working

If the system boots with the receiver and/or display powered down, then no sound - ever. I'd like to resolve that, too, but that's how this setup has always behaved for me. The "restarting x kills sound" thing is relatively new.

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## Tatsh

Would really like to know if you guys solve this. I have the exact same issue and this is an 8200. Maybe 8200 is just crap. I sure feel like it lately. It's barely usable with Kwin compositing.

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