Comment 121 for bug 745112

Please attach xrandr --verbose output. Also please boot with drm.debug=0xe attached to your kernel cmdline, try to set a low working resolution and then a high non-working resolution and attach the entire dmesg. Please ensure that the attached dmesg is complete, if stuff at the beginning is missing you need to increase the log buffer with log_buf_len=2M or even larger.

Also please provide the output of lspci -nn for you gpu.