https://bugs.freedesktop.org/show_bug.cgi?id=98324
Bug ID: 98324 Summary: amd-staging-4.7: problems with unblanking displays when monitors are switched off Product: DRI Version: unspecified Hardware: Other OS: All Status: NEW Severity: normal Priority: medium Component: DRM/AMDgpu Assignee: dri-devel@lists.freedesktop.org Reporter: bugspam@moreofthesa.me.uk
Created attachment 127405 --> https://bugs.freedesktop.org/attachment.cgi?id=127405&action=edit Kernel log extract, showing the unblanking failure.
Setup: RX 470 with two monitors attached – one via DVI-and one via HDMI. (Both are AOC monitors.)
* Ensure that outputs are blanked (via xset, time-out or similar). * Switch off the monitors. * Unblank the outputs. * Switch on the monitors.
Invariably, in this situation, the DVI-connected monitor is unblanked and displaying what it should be, but the HDMI-connected monitor is receiving no signal (or at least nothing to display) and is therefore displaying nothing.
The HDMI-connected monitor can be restored by using xrandr to change mode or by blanking and unblanking – so long as it's switched on while doing so.