Multi screen and graphics cards failed with radeon driver on debian stretch

[pbasnews-deb at yahoo.fr]

Wonderfull! Thxs a lot Michel! Your way working well.

Here what I'm done (if anyone need it):
I removed xorg.conf (I think that your solution working with it anyway)

I'm login on kde with user login and open a terminal (konsole) and I list my 2 graphics cards:
xrandr --listproviders
Providers: number : 2
Provider 0: id: 0x99 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 2 outputs: 3 associated providers: 1 name:ATI Radeon X1550 64-bit @ pci:0000:02:00.0
Provider 1: id: 0x53 cap: 0xf, Source Output, Sink Output, Source Offload, Sink Offload crtcs: 2 outputs: 2 associated providers: 1 name:ATI Radeon 3000 Graphics @ pci:0000:01:05.0

and I launch:
/usr/bin/xrandr --setprovideroutputsource "ATI Radeon 3000 Graphics @ pci:0000:01:05.0" "ATI Radeon X1550 64-bit @ pci:0000:02:00.0"

At this point, I can see my 3 monitors in KDE system setting (before kde could see only one graphics cards with 2 monitors):
- VGA-1 (on ATI Radeon X1550)
- DVI-0 (on same graphic card ATI Radeon X1550)
- and VGA-1-0 (disabled disabled and kde didn't manage to enabled it) on ATI Radeon 3000

Then I use xrandr to setting/enable them:
/usr/bin/xrandr --output DVI-0 --mode 1680x1050 --primary --output VGA-1 --mode 1024x768 --left-of DVI-0 --output VGA-1-0 --mode 1280x1024 --right-of DVI-0

After kde start I need to launch both commands, then I put them in a nice script that I launch in autostart kde (in ~/.xsession it didn't work, maybe because I use sddm and not kdm anymore?):

ls ~/.config/autostart-scripts/
lrwxrwxrwx  1 pascal pascal   38 juil.  3 10:27 My3Screens.bash -> /home/pascal/config/My3Screens.bash

ty I can go back to work now :-)

Pascal

--------------------------------------------
En date de : Lun 3.7.17, Michel Dänzer <michel at daenzer.net> a écrit :

 Objet: Re: Multi screen and graphics cards failed with radeon driver on debian stretch
 À: pbasnews-deb at yahoo.fr
 Cc: xorg-driver-ati at lists.x.org
 Date: Lundi 3 juillet 2017, 5h19
 
 On 30/06/17 10:53 PM, pbasnews-deb at yahoo.fr
 wrote:
 > Without xorg.conf, I have only
 one half of screen. I can enable 2 screens of same
 > graphics card with xrandr of course (and
 kde system setting too)
 > 
 > But unfortunaly I can not use xrand to
 enable my 3rd screen connected on my second
 > graphic cars
 >
 DISPLAY=:1 /usr/bin/xrandr --output VGA-0 --mode
 1280x1024
 > and
 >
 DISPLAY=:1 xrandr --setprovideroutputsource "ATI Radeon
 3000 Graphics @ pci:0000:01:05.0"
 >
 
 > return is: "Can't open
 display :1"
 
 [...]
 
 > What do you mean by
 "Oops, the DISPLAY=:1 wasn't supposed to be
 there." ?
 
 It means you
 should run just
 
  xrandr
 --setprovideroutputsource "ATI Radeon 3000 Graphics @
 pci:0000:01:05.0" "ATI Radeon X1550 64-bit @
 pci:0000:02:00.0"
 
 
 -- 
 Earthling
 Michel Dänzer               |              
 http://www.amd.com
 Libre
 software enthusiast             |            
 Mesa and X developer