On Wed, Apr 29, 2015 at 08:04:35PM +0100, Nick Booker wrote: > Hi. > > I'm getting display corruption during login on the latest Debian 8 > (Jessie), installed from scratch on an emptied hard disk. > > I have the MATE desktop environment, and am using the nouveau graphics > driver. > > This didn't happen with my previous OSes (Debian Wheezy, Linux Mint 17.1 > or Parabola GNU/Linux bleeding edge). > > If I boot my machine from cold, having just plugged in: > > Boot messages progress to lightdm fine > All looks normal while interacting with lightdm > After entering my login details, before showing the usual MATE desktop > elements and wallpaper, the screen is corrupted for a couple of seconds. > During that period it is green with various coloured (mostly purple) > dots in seemingly-random places. > > If I then reboot or shut down and start back up without unplugging and > waiting for the motherboard to power down, during my next login, rather > than the green with purple dots, I get a collage of bits of my previous > session's windows (even some long closed before shutdown) displayed. > > Please can anyone help me to debug and fix this issue? > > I haven't filed a bug because I don't know where the issue lies at the > moment (kernel/systemd/xf86-video-nouveau/...?)
I would suggest filing a bug against the video driver (nouveau, in this case). I would guess that, as an optimization, it's allocating video memory, but not clearing it. Then, when the display comes on, the contents of that memory is shown. I suspect the fix would be to either zero the video memory (so giving you a black screen) or to not activate the display until the first image has been drawn to it. There is a possible security angle here, so report it as a bug and, if it's actually the kernel that should have been responsible for clearing that memory, I'm sure the nouveau people will re-assign the bug. > > I don't mind poking around source code if necessary with a bit of > hand-holding. > > Selected details from lspci, glxinfo and dmesg in the following paste: > > [1]http://paste.debian.net/169967/ > > Thanks, > > Nick > > -- > Sent from my Android device with K-9 Mail. Please excuse my brevity. > > References > > Visible links > 1. http://paste.debian.net/169967
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