https://bugs.freedesktop.org/show_bug.cgi?id=102319

Bug ID: 102319 Summary: Crashes and freezes when switching VTs Product: DRI Version: XOrg git Hardware: Other OS: All Status: NEW Severity: normal Priority: medium Component: General Assignee: dri-devel@lists.freedesktop.org Reporter: marcin.marcin.m@gmail.com

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 for 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 TTY 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, the 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 output in the dmesg log: https://pastebin.com/FgzZLEGg

I asked about it on #nouveau and I was told that since the intel driver takes 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 i5-7500K as the CPU/integrated GPU, with fairly same software stack.

OS: Arch Linux, DE: Cinnamon