<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - WQHD Displayport only 27 Hz" href="https://bugs.freedesktop.org/show_bug.cgi?id=93343#c6">Comment # 6</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - WQHD Displayport only 27 Hz" href="https://bugs.freedesktop.org/show_bug.cgi?id=93343">bug 93343</a> from <a class="email" href="mailto:mario.kleiner@tuebingen.mpg.de" title="Mario Kleiner <mario.kleiner@tuebingen.mpg.de>"> Mario Kleiner</a> <pre>One thing you could try is booting with the kernel command line parameter radeon.audio=0 and see if that helps. I also have some DisplayPort panel from Dell with 2560x1440 native resolution which runs at 67 Hz refresh rate when the kernel/X-Server/RandR think it is running at 60 Hz. Setting other than the native resolution will produce too high or too low refresh rates and/or corrupted display. Disabling audio over Displayport fixed the problem for me. The bug there seems to be some misprogramming of clocks or low level mode timings when audio over Displayport is enabled. This was introduced around Linux 4.0 with DP audio enablement iirc and might still be an issue in the current 4.4-rc kernel. I told Alex and Michel about it around that time and they knew that there might be still work to do to fixup some clock calculations for DP audio. -mario</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>