I have a weird problem while switching vts
I have a dual-GPU setup: intel i5-5200U as the default OpenGL renderer and
GeForce 940M as the discrete card. I'm using the intel modesetting driver f=
or
the Intel graphics and xf86-video-nouveau for DRI_PRIME.
If I run SDDM/LXDM as my display manager (on Arch Linux), then switch the T=
TY
to tty2, then switch back to tty7 (DM), I get only a blinking cursor.
If I run LightDM as my display manager, it survives a tty switch, but if I
start an X server in tty2 and then switch directly to tty7, LightDM crashes.
If I switch tty2 -> tty3 (no x server) -> tty7, on the other hand, th=
e DM does
*not* crash.
The whole problem doesn't occur when using the `nomodeset` kernel option, (=
i.e.
when my DE runs in software rendering mode)
Whenever I switch the ttys or when I launch the DM I get the following outp=
ut
in the dmesg log: https://pastebi=
n.com/FgzZLEGg
I asked about it on #nouveau and I was told that since the intel driver tak=
es
care of the rendering, it is the one to blame here.
On the intel side, the problem occurs with both xf86-video-intel and the
modesetting driver
The problem only occurs with the X server that is launched by a DM. If I run
startx directly from the tty on both vts, everything works correctly.
It is not observed on a machine without nvidia graphics and with intel i5-7=
500K
as the CPU/integrated GPU, with fairly same software stack.
OS: Arch Linux, DE: Cinnamon