Bug 39612

Summary:	radeon blocks with new style fencing
Product:	Drivers	Reporter:	Linas (linas_fi)
Component:	Video(DRI - non Intel)	Assignee:	drivers_video-dri
Status:	NEEDINFO ---
Severity:	normal	CC:	alan, alexdeucher
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.6.2	Subsystem:
Regression:	Yes	Bisected commit-id:
Attachments:	Xorg log Xorg log mieq Other Xorg log

Description Linas 2011-07-19 18:45:39 UTC

I am using a Radeon HD 3600 in kernel 2.6.36 with xf86-video-ati (KMS). Since 2.6.37 when starting the X server the screen goes black and never shows the desktop.

kernel 2.6.36
startx -> Screen goes black -> The wallpaper appears -> The DE loads

kernel >= 2.6.37
startx -> Screen goes black -> You can't switch virtual terminals -> REISUB -> Downgrade kernel

Reproducible: Always

Bisecting shows that it started failing at d0f8a854c340986359a3b0a97e380c71def7a440: drm/radeon/kms/r6xx+: use new style fencing (v3)

http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.37.y.git;a=commit;h=d0f8a854c340986359a3b0a97e380c71def7a440

Downstream bug https://bugs.archlinux.org/task/23422

Comment 1 Alex Deucher 2011-07-20 04:19:06 UTC

Please attach your xorg log and dmesg output.  Does booting with radeon.no_wb=1 on the kernel command line in grub help?

Comment 2 Linas 2011-08-01 22:29:21 UTC

Created attachment 67342 [details]
Xorg log

Sorry for the delay. I'm attaching the file.
The radeon.no_wb=1 workaround does indeed work. Much appreciated.
Instead of showing only the mouse pointer (if lucky), shows the full screen again.

Comment 3 Alan 2012-08-24 15:33:20 UTC

Is this still needing workarounds or can I close it ?

Comment 4 Linas 2012-10-21 19:31:38 UTC

Created attachment 84201 [details]
Xorg log mieq

Testing with 3.6.2, radeon.no_wb=1 is still needed, although it seems a bit better.
You can get -with a little difficulty- to switch virtual terminals, so it is possible to SIGINT the xserver. Interestingly, although the first startx leads to a blank screen, a second startx runs the DE without being apparently affected. ?!
Booting with radeon.no_wb=1 the DE shows directly the first time, as it should.

In one failed instance, the Xorg log showed errors of «[mi] EQ overflowing.», «[mi] EQ overflow continuing.  100 events have been dropped.», «[mi] EQ overflow continuing.  200 events have been dropped.»... I am attaching this log.

Comment 5 Linas 2012-10-21 19:34:45 UTC

Created attachment 84211 [details]
Other Xorg log

Another failed Xorg log, this time without overflowing errors.

Comment 6 Michel Dänzer 2013-12-11 04:07:12 UTC

Is this still an issue with current kernels and userspace stack?

Comment 7 Linas 2013-12-30 19:29:47 UTC

I still have video problems, although causing a freeze at some random point*, rather than a black screen after boot.


* Or you can make it deterministic by running something like /usr/lib/xscreensaver/kumppa ;)

Comment 8 Michel Dänzer 2014-01-06 09:20:57 UTC

(In reply to Linas from comment #7)
> I still have video problems, although causing a freeze at some random
> point*, rather than a black screen after boot.

Are you sure it's still the same problem? Does no_wb=1 still work around it?