Comment 17 for bug 958279

Ubuntu 14.04 here, Radeon HD 8490. The bug has bit me once (fail to wake up from DPMS screen off). What happens frequently is that, with DPMS on (I use "xset dpms 0 0 600"), it behaves for a while, then keeps blanking the screen so often that it becomes unusable. I also have "xset -s" (no screensaver). If I do "xset -dpms" then the machine is fine but of course the display stays on. I use i3wm, am not using any desktop environment that would blank the screen for me. I have now generated an xorg.conf as suggested in the previous comment, and will wait and see how it does.