mythfrontend segmentation fault, problem with video

skwang · Last edited by skwang on Sun Apr 19, 2009 9:18 pm; edited 2 times in total

My problem is with mythfrontend (I think this not a problem for the Multimedia section) and any mythtv application (including mythtv-setup). Any time I try to start the executable it crashes and returns a segmentation fault. I've have a strace, the output of 'strace mythfrontend', and a gdb backtrace (with no debugging symbols though), the output of 'gdb mythfrontend -x gdbcommand', and can post them if requested.

Here is the strange part. I can ssh into the mythfrontend system with X forwarding, and start mythfrontend without problem through ssh. This leads me to think that the problem I have is with the video drivers. Specifically this problem showed up after upgrading to xorg-server-1.5.3-r5. The machine is an Asus-Pundit-S, with an sis chipset (SiS 650). So I am using xf86-video-sis-0.10.0 as my video driver.

What I have tried:

1. Since gcc was upgraded I went ahead and recompile the entire system (emerge -e system and emerge -e world) including the kernel.

2. revdep-rebuild, as usual.

3. recompiled xf86-video-sis-0-10.0

4. upgraded to xf86-video-sis-0.10.1 (downgraded after this failed)

I should point other other multimedia applications work as xine runs without problem. I believe opengl works too as glxgears runs.

If you have any suggestions, please let me know.

Here is my emerge --info:

PraetorZero · Apprentice Joined: 11 Dec 2004 Posts: 239 Location: /home

This is actually kind of funny, I just did all of this myself (including SSHing to the box) trying to troubleshoot this problem. I'm running across the same problem. I'm on a brand new build using x11-drivers/xf86-video-radeonhd-1.2.5 x11-base/xorg-server-1.5.3-r5 x86_64-pc-linux-gnu-4.3.2 media-libs/mesa-7.4.

I was actually thinking this might be a mesa bug since I found this bug on their bugzilla. But I believe I need mesa-7.4 to get acceleration for my particular card.

SO, my question is, what version of mesa do you have installed?
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skwang · Posted: Tue Apr 14, 2009 1:51 pm Post subject:

I am using media-libs/mesa-7.3-r1, which is the latest stable version on x86.

Am I to gather from your post that you are using mesa-7.4? That doesn't mean mesa isn't the culprit, as we have two different systems. I'll try playing around with the mesa versions (downgrading to 7.3, upgrading to 7.4) and see if that makes any difference. (I am at work).

skwang · Posted: Tue Apr 14, 2009 10:54 pm Post subject:

PraetorZero-

I upgraded to mesa-7.4 and that actually solved my problem. Now mythfrontend starts! So the solution (for me was):

1 Add keyword ~x86 to mesa.
2 upgrade to media-libs/mesa-7.4
3 recompile xorg-server and mythtv.
4 revdep-rebuild
5 reboot

I don't know if recompiling, revdep-rebuild, and rebooting mattered at all.

Finally, the version of mythtv on my system is media-tv/mythtv-0.21_p19961-r1.

PraetorZero · Apprentice Joined: 11 Dec 2004 Posts: 239 Location: /home

Shoot. I was hoping that wouldn't fix your problem, because mine still exists.

I'm going to recompile myth with the debug use flag and see what I can get with a trace of the segfault. I'm glad it worked for you though!
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colp · n00b Joined: 19 Apr 2009 Posts: 11

I had the same problems.
Heres my new xorg.conf

PraetorZero · Apprentice Joined: 11 Dec 2004 Posts: 239 Location: /home

PraetorZero · Apprentice Joined: 11 Dec 2004 Posts: 239 Location: /home

PraetorZero · Apprentice Joined: 11 Dec 2004 Posts: 239 Location: /home

Okay, I finally got it working without issues. The problem is with media-libs/mesa-7.4

I applied this patch from their bugzilla this evening.

I now have xv acceleration with glx enabled using the radeonhd-1.2.5 driver. The bug doesn't specifically mention it only affecting a single card, but it's well worth the try.
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mitchd123 · n00b Joined: 13 Jan 2004 Posts: 40

I was having the same problem with the segmentation fault when I tried to open mythfrontend, and it would come and go at random times.

The solution for me was to re-compile the nvidia-drivers and set opengl to nvidia

eselect opengl set nvidia
exit out of x
reload the nvidia modules: modprobe -r nvidia
restart x

skwang · Posted: Thu Apr 23, 2009 11:57 pm Post subject:

It seems that while there are multiple "solutions" to the problem, the cause is the same, some bug in OpenGL that causes mythtv to seg. fault. I suspect the real "solution" will be to wait for the next version of mesa, which hopefully will have the patch PraetorZero mentioned.

Or if you have an nvidia card and use nvidia drivers, and use their OpenGL libraries which doesn't seem to have this problem. I'm reluctant to mark this as truly "solved" though, because the bug in mesa remains.