Signal unstable over Display Port on 2560x1440 monitor

Submitted by Tvrtko Ursulin

Assigned to Default DRI bug account

Link to original bug (#48772)

Description

AMD G-T56N (Radeon HD 6310) hardware with kernel 3.4-rc3 with a Xorg DDX from 28.03.2012. plus a tiling patch from bug 47765.

Dell U2711 monitor native resolution is 2560x1440 on which Display Port connection is unstable.

I get periodic very brief flashes of vertical noise areas, full screen width, at various vertical positions, but possible always at least roughly the same height. Then the screen goes black for a second, comes back for a while, flashing, or straight back to black and so on. Timings do not look regular, although I haven't actually timed and analysed them.

Bringing the resolution down to 1920x1200 and it works fine.