Bug 675532

Created attachment 477289 [details]
Don't let the Xorg server crash if XV is not initialized

This patch adds a check to avoid the crashes if XV is not initialized.
After the patch X11 server loads properly:

[ 21670.571] (==) intel(0): Intel XvMC decoder disabled
[ 21671.225] (II) v4l: /dev/video0 open ok
[ 21671.225] (II) v4l: /dev/video0 device supports overlay mode.
[ 21671.225] (II) VIDIOCSPICT / VIDIOC_S_FMT: 22
[ 21671.225] (II) VIDIOCSPICT / VIDIOC_S_FBUF: 22
[ 21671.225] (II) VIDIOCSPICT / VIDIOC_S_FMT: 22
[ 21671.225] (II) VIDIOCSPICT / VIDIOC_S_FBUF: 22
[ 21671.225] (II) v4l: add attr XV_ENCODING
[ 21671.225] (II) v4l: add attr XV_BRIGHTNESS
[ 21671.225] (II) v4l: add attr XV_CONTRAST
[ 21671.225] (II) v4l: add attr XV_SATURATION
[ 21671.225] (II) v4l: add attr XV_HUE
[ 21671.225] (II) VIDIOCGAUDIO / VIDIOC_G_AUDIO: 9
[ 21671.225] (II) v4l: add attr XV_FREQ
[ 21671.225] (II) v4l: saving config into driver data
[ 21671.225] (II) v4l: /dev/video0 init finished.
[ 21671.257] (II) v4l: init done, 1 device(s) found

The above messages are with the debug messages enabled. The last message indicates that v4l driver loaded properly.

I added a small patch at the Intel driver, as it should be supporting Xv:

diff -r 9a863fcd4479 src/intel_video.c
--- a/src/intel_video.c	Sun Feb 06 15:38:05 2011 -0500
+++ b/src/intel_video.c	Sun Feb 06 15:39:08 2011 -0500
@@ -398,6 +398,8 @@
 		adaptors[num_adaptors++] = overlayAdaptor;
 
 	if (num_adaptors) {
+		xf86DrvMsg(scrn->scrnIndex, X_WARNING,
+			   "Xv enabled with %d adaptors.\n", num_adaptors);
 		xf86XVScreenInit(screen, adaptors, num_adaptors);
 	} else {
 		xf86DrvMsg(scrn->scrnIndex, X_WARNING,

And a log at v4l driver to show when it detects that Xv is not supported. The result logs are:

[ 27315.881] (EE) v4l: video screen doesn't have Xv extension.
[ 27315.881] (WW) intel(0): Xv enabled with 2 adaptors.

What's happening here is that the v4l driver was loaded just before the Intel register for Xv. Due to that, it was failing.

Some change is needed to make sure that v4l driver will be loaded only after having all adapters registered.

Created attachment 477367 [details]
Don't let the Xorg server crash if XV is not initialized v2

Version 2: return NULL instead of 0 and sets num = 0

(In reply to comment #2)
> I added a small patch at the Intel driver, as it should be supporting Xv:
> 
> diff -r 9a863fcd4479 src/intel_video.c
> --- a/src/intel_video.c Sun Feb 06 15:38:05 2011 -0500
> +++ b/src/intel_video.c Sun Feb 06 15:39:08 2011 -0500
> @@ -398,6 +398,8 @@
>    adaptors[num_adaptors++] = overlayAdaptor;
> 
>   if (num_adaptors) {
> +  xf86DrvMsg(scrn->scrnIndex, X_WARNING,
> +      "Xv enabled with %d adaptors.\n", num_adaptors);
>    xf86XVScreenInit(screen, adaptors, num_adaptors);
>   } else {
>    xf86DrvMsg(scrn->scrnIndex, X_WARNING,
> 
> And a log at v4l driver to show when it detects that Xv is not supported. The
> result logs are:
> 
> [ 27315.881] (EE) v4l: video screen doesn't have Xv extension.
> [ 27315.881] (WW) intel(0): Xv enabled with 2 adaptors.
> 
> What's happening here is that the v4l driver was loaded just before the Intel
> register for Xv. Due to that, it was failing.
> 
> Some change is needed to make sure that v4l driver will be loaded only after
> having all adapters registered.

I've patched the driver to only talk with Xv during device open and this didn't solve at all.

What happens is that the Intel driver registers only textured video. I tested with nouveau driver and got similar results. So, the issue is not related to the
initialization order.

Yet, the fix at attachment 477367 [details] is needed, otherwise trying to load v4l driver will cause a crash during X start, if a video board with overlay support is connected and its driver is loaded.

This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle.
Changing version to '19'.

(As we did not run this process for some time, it could affect also pre-Fedora 19 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 19 End Of Life. Thank you.)

More information and reason for this action is here:
https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora19

This message is a notice that Fedora 19 is now at end of life. Fedora 
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