Arch Linux

p4l4cl][n

Member

Registered: 2011-11-16

Posts: 43

[SOLVED] XRandR only one monitor can be at max resolution

Hey guys, I have problem with XRandR after update. It (IMHO correctly) detects two monitors:

Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
DisplayPort-1 disconnected (normal left inverted right x axis y axis)
HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 298mm
   1920x1080     60.00*+  50.00    59.94  
   1920x1080i    60.00    50.00    59.94  
   1680x1050     59.88  
   1600x900      59.98  
   1280x1024     75.02    60.02  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.08    60.00  
   832x624       74.55  
   800x600       75.00    60.32  
   720x576       50.00  
   720x576i      50.00  
   720x480       60.00    59.94  
   720x480i      60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
DVI-0 connected (normal left inverted right x axis y axis)
   1920x1080     60.00 +
   1600x1200     60.00  
   1680x1050     59.88  
   1280x1024     75.02    60.02  
   1440x900      74.98    59.90  
   1360x768      60.02  
   1152x864      75.00  
   1280x720      59.97  
   1024x768      75.08    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   640x480       75.00    72.81    66.67    60.00  
   720x400       70.08  

When I try to use XRandR like this

xrandr --output HDMI-0 --auto --output DVI-0 --auto --left-of HDMI-0

it shows desktop only on one monitor and the other one reports "no signal". The monitor which is working is the one at 0x0.

The thing is, this does work when only one of the monitors is at max resolution (1920x1080). Meaning if I do something like

xrandr --output DVI-0 --mode 720x400 --right-of HDMI-0

afterwards I do get screen on both monitors.

It worked before kernel update, so it *does* work in linux-4.0.1 and *does not* in linux-4.0.4.

I'm using radeon R9

01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Tahiti PRO [Radeon HD 7950/8950 OEM / R9 280]

XServer doesn't show anything relevant in the log, neither does journalctl. Can anyone help me debug this further? I can probably live with 4.0.1, but it would be nice  to keep whole system updated.

Thanks for help :)

Last edited by p4l4cl][n (2015-06-08 17:26:19)

Skeer

Member

Registered: 2009-09-17

Posts: 20

Re: [SOLVED] XRandR only one monitor can be at max resolution

Hey I had a similar issue as you here

Try running

pacman -Syu

to get linux 4.0.5. That solved my issue

p4l4cl][n

Member

Registered: 2011-11-16

Posts: 43

Re: [SOLVED] XRandR only one monitor can be at max resolution

seems to work, thanks for info

Marking as solved