[EXA] Radeon HD 5450 suddenly blanks screen or shows old content
Submitted by Markus Näher
Assigned to xf86-video-ati maintainers
Description
Some Background info:
I'm using the radeon driver for my Radeon HD 5450 on ArchLinux (x86_64) with XFCE desktop.
The issue occurs since one of the latest software updates, on two PC's with a Radon HD 5450, both with two screens attached. Because of the two PC's, I think a hardware defect is unlikely. On one of the PC's, I've tried a Radeon HD 7750 (borroewd from a friend), and the issue was gone until I had to give it back. I did not change any settings during the test.
This is what happens:
Sometimes, it "forgets" what it should display on the screen and suddenly, I see a mix of an old screen content, with some black areas and (most times, but not always) a part of the xscreensaver dialog. The issue can be triggered by opening a window, menu, or dialog or even some animation within a window. One thing that often "works" as a trigger is the "blue arrow" animation of firefox when I start a download. Sometimes it can just be the blinking of the cursor in a text editor like geany. But the trigger is not always that obvious.
When I try to force a redraw of the whole screen by switching between virtual desktops or between console and X, it shows the correct screen content for a split second, and then switches to the wrong display again. It looks like flickering between two states.
The only way (other than rebooting) I found out to stop it is to identify the trigger window and close (or hide) it. Sometimes I can restore it without triggering again, sometimes not. Sometimes it stops after a few minutes, sometimes not. Until it stops, the PC is completely unusable. But even identifying the right window and trying to hit the minimize or close button with the mouse when you can't see what you're doing is really hard.
As of the PC's has long-running jobs that can not be suspended and resumed, rebooting is mostly not an option.
I'm not 100% sure, but I think it happens after the lockscreen once was activated, either manually or by idle timer. From reboot to first lockscreen, I think I haven't experienced it yet. Other than lockscreen, I don't use any screensaver.
The screen content that is displays can be really old: Yesterday, I changed my desktop background, and today, I saw the old background when it happened (no reboot in between).
I really would like to keep my 5450's, because they are really good office cards (passive cooling, dual DVI-I, ...) and even good enough for some gaming. But the issue literally drives me crazy.