Created attachment 47090 [details] [review]
dmesg before echo DDIS > switch
When I try to switch to my radeon HD 6630 discrete GPU on my sandybridge Sony VAIO VPCSB from intel integrated GPU, I get a segmentation fault in X and even VT output to screen stops. When I ssh in from another computer and switch back to the intel GPU, my screen comes back and I can restart X and log in again.
Steps I performed to produce this:
1) make sure both intel and radeon kernel modules are loaded
2) echo DDIS > /sys/kernel/debug/vgaswitcheroo/switch
3) log out of X. At this point the screen is unresponsive and I cannot use the machine or log into X because it has segfaulted
4) ssh in from another computer
5) echo DIGD > /sys/kernel/debug/vgaswitcheroo/switch
7) switch to VT1 of first computer
8) login and type: sudo service gdm restart from first computer
9) log back into X on first computer
Created attachment 47091 [details] [review]
dmesg after echo DDIS > switch
Created attachment 47092 [details]
Xorg.0.log before echo DDIS > switch
Created attachment 47093 [details]
Xorg.0.log after echo DDIS > switch
My setup is:
kernel 2.6.39 final
You have a muxless laptop which means the discrete card is not connected to any
displays. You won't be able to use the discrete card until the xserver gets
the ability to decouple rendering and display (i.e., rendering with one GPU,
displaying with another). It's a huge amount of work and won't be supported
any time some.
*** Bug 41340 has been marked as a duplicate of this bug. ***
*** Bug 41467 has been marked as a duplicate of this bug. ***
*** Bug 39218 has been marked as a duplicate of this bug. ***
*** Bug 46270 has been marked as a duplicate of this bug. ***
This is supported with xserver 1.14 and newer.
on Feb 26, 2017 at 14:46:38.
(provided by the Example extension).