<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL] intel_dp_start_link_train ERROR 5.4Gbps rate without HBR2/TPS3 support" href="https://bugs.freedesktop.org/show_bug.cgi?id=92932#c6">Comment # 6</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [SKL] intel_dp_start_link_train ERROR 5.4Gbps rate without HBR2/TPS3 support" href="https://bugs.freedesktop.org/show_bug.cgi?id=92932">bug 92932</a> from <a class="email" href="mailto:timur.alperovich@gmail.com" title="Timur Alperovich <timur.alperovich@gmail.com>"> Timur Alperovich</a> <pre>Jani, I attempted to plug in a 4k monitor over the display port. The monitor produced a black screen. At lower resolution (2560x1440), the image is displayed, but at 3840x2160 I get a black screen with the following warnings: [ 1814.843637] [drm:gen8_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun [ 1815.628547] [drm:intel_dp_start_link_train [i915]] *ERROR* 5.4 Gbps link rate without HBR2/TPS3 support I'm also seeing this warning when attaching/removing a display: [ 1806.466752] WARNING: CPU: 0 PID: 1434 at drivers/gpu/drm/i915/intel_pm.c:3537 skl_update_other_pipe_wm+0x138/0x140 [i915]() [ 1806.466754] WARN_ON(!wm_changed) It seems benign however. If I switch to using HDMI and try the same resolution as above at 30Hz, the image is also displayed correctly. This is with the drm-intel-nightly build as of November 30th. Let me know if I can do any other tests, open a different bug, or attach any logs that would be helpful.</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>