I'm getting a similar bug in 16.04 on my Inspiron 6400 with X1300 and a 1680x1050 display. I have disabled graphical overlays during boot because I prefer to see boot text. Corruption starts after the switch from ordinary VGA text mode to a high resolution text mode which I assume is implemented using a graphics mode. In that text mode, corruption is mostly flashing long vertical bright bars rising from the bottom. In X, corruption is mostly short horizontal lines on a dark area to the right of a bright area, and the long vertical bars seen in text mode rarely appear.
The corruption never propagates via screen operations like scrolling, so it doesn't seem to be in memory. It's as if there is something wrong with the video mode or LVDS communication with the display. I made the corruption go away in X by first switching to a lower resolution via "xrandr --output LVDS --mode 1400x1050" and then going back to the native resolution via "xrandr --output LVDS --mode 1680x1050". I'm not getting any corruption in Windows 7, so I don't think this is a hardware problem. ** Attachment added: "Vertical bar corruption in text mode" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/539630/+attachment/4599344/+files/P3140013.JPG -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/539630 Title: Xorg display corruption, Dell Inspiron 6400, Lucid Beta ISO test To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/539630/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp