<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [HSW DP] Blank screen at 3840x2160 resolution (both framebuffer and Xorg)" href="https://bugs.freedesktop.org/show_bug.cgi?id=86377#c11">Comment # 11</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [HSW DP] Blank screen at 3840x2160 resolution (both framebuffer and Xorg)" href="https://bugs.freedesktop.org/show_bug.cgi?id=86377">bug 86377</a> from <a class="email" href="mailto:brian.campbell@editshare.com" title="Brian Campbell <brian.campbell@editshare.com>"> Brian Campbell</a> <pre>After some more testing, I've determined that I can get the full resolution to work, at 30 Hz, with "xrandr --display DP1 --mode 0x47" (in both 3.16 and a build of drm-intel-nightly; I could have sworn I'd tried that before doing this testing, but it seems to be working now). Using the full 60Hz refresh rate (just letting it auto-detect, or using --mode 3840x1920, or --mode 0x46), I the same error on 3.16 and drm-intel-nightly, with just a slight difference in the exact string. Now the error is: Nov 25 20:24:13 scratch kernel: [47301.178057] [drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR* uncleared fifo underrun on pipe A Nov 25 20:24:13 scratch kernel: [47301.178087] [drm:ironlake_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun If it would be useful for me to dump any more information on the drm-intel-nightly kernel, let me know.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are on the CC list for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>