After activating the second GPU (setprovideroutputsource) changing any XRandr setting leads to inavlid dpi and wrong framebuffer size
Submitted by Jan Burgmeier
Assigned to Xorg Project Team
Description
Created attachment 119034 Xrandr output before setting the dpi manually
Hi,
My setup is the following:
PC: HP T620 Plus with two AMD graphics card Monitors: 3 Dell 4k Monitos running at 1920x1080. Two are attached to the primary card and one to the secondary card.
After activating the secondary GPU with "xrandr --setprovideroutputsource" changing any XRandr setting (resolution, rotation, ...) leads in a too small framebuffer. It seems that the dpi is wrongly set. It is also not possible to change the framebuffer with "xrandr --fb". The following commands will fix the problem:
user> xrandr --dryrun --verbose --fb 4080x1920 screen 0: 4080x1920 0x0 mm infdpi
user> xrandr --verbose --fb 4080x1920 screen 0: 4080x1920 0x0 mm infdpi X Error of failed request: BadValue (integer parameter out of range for operation) Major opcode of failed request: 140 (RANDR) Minor opcode of failed request: 7 (RRSetScreenSize) Value in failed request: 0x0 Serial number of failed request: 52 Current serial number in output stream: 54
user> xrandr --verbose --dpi 96 screen 0: 4080x1920 1079x507 mm 96.00dpi
The following versions were used: Xorg-1.17.2 xf86-video-ati latest git version (ce9914a) mesa-11.0.0 libdrm-2.4.64 libLLVM-3.7
It does not matter if using DRI2 or DRI3. It does not matter if ColorTiling2D is on or off.
Attachment 119034, "Xrandr output before setting the dpi manually":
xrandr_output_before_dpi_change