Le 30 mai 2019 à 18:01, Harry Wentland <hwentlan@xxxxxxx> a écrit : > > On 2019-05-27 10:58 a.m., Gaël HERMET wrote: >> Hi, >> >> I have been facing an issue with my 5K display (iiyama ProLite >> XB2779QQS-S1). >> >> It works fine as long as it is the only active monitor, as soon as I >> activate another monitor the main one (5k) can't display more than 4k. >> >> Debug using "echo 0x4 > /sys/module/drm/parameters/debug" show this : >> mai 23 09:01:22 bureau-gael /usr/lib/gdm3/gdm-x-session[3465]: (EE) >> AMDGPU(0): failed to set mode: Invalid argument >> mai 23 09:01:22 bureau-gael kernel: [drm:dce112_validate_bandwidth >> [amdgpu]] dce112_validate_bandwidth: Bandwidth validation failed! >> >> I disabled the check by forcing is_display_configuration_supported to >> return true in dce_calcs.c and it works fine. >> >> Anything I can do to correct this bandwidth calculation ? >> > > The bandwidth formulas come from our HW teams and usually leave a good > margin of error. Changing the formulas to allow for your case isn't a > correction as it might cause issues in certain scenarious, i.e. there's > no more guarantee that things work as expected. > > Examples are 4k video playback (especially multiple videos), gaming. > Anything that does a lot of GPU memory access. > > Issues that might appear are underflow, i.e. white lines on the screen. > In extreme cases underflow might even hang the entire display pipe. > > Harry Ok I understand. Is there any reason why it works without any trouble or setting to mess with in both Windows and MacOS ? This setup is not that rare, 5k iMacs with Radeon graphics have existed for years now and they all support external displays fine. Thanks again, Gaël. > >> >> _______________________________________________ >> amd-gfx mailing list >> amd-gfx@xxxxxxxxxxxxxxxxxxxxx >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
