X windows video freeze - KV 5.10.x

Originally Posted by GazL Thanks rd. I've now switched to kms/modesetting driver, with compton. I hit a problem with tiled wallpapers loaded via wmsetbg not displaying correctly under compton, but fullscreen wallpapers seem to display ok, so I can workaround that. I'd had a good couple of weeks since my last lockup using the 'intel' driver so it'll take me a while before I'll be confident there's no problem with modesetting. I will miss being able to do silly stuff like /usr/libexec/xscreensaver/glschool -root to have animated root windows when I'm feeling in the mood for it, but I can probably do something with fvwm's StayOnBottom style to simulate that. Anyway, I'll report back if I have any further issues with the kms/modesetting driver.

Could you possibly post the principal scheme on your hardware? You use FVWM as main GUI WM? You launch all, including KDE / Qt applications thru this WM? Do you use a DM or start via startx / xinit?

There are scattered reports in this thread that the Intel video driver will function reliably IF you have one or more kernel CL options invoked. Since the lockups / freezes are random, it could take some time to verify their validity. Ultimately, I believe that Intel would need to actively address these limitations or explicitly tell users about the inherent restrictions.

Originally Posted by rdsherman Could you possibly post the principal scheme on your hardware? You use FVWM as main GUI WM? You launch all, including KDE / Qt applications thru this WM? Do you use a DM or start via startx / xinit?

Sure.

Intel Broadwell-U i3-5157u laptop with Iris 6100 Integrated graphics (rev 09)
No external monitor, just the laptops panel.
Slackware64-current and CRUX 3.6 dual boot.
Kernels 5.5.0 - 5.9.16 unaffected.
fvwm 2.6.9 window manager, no compositor.
Use both startx (crux) and xdm (slackware).
Was using xf86-video-intel (tearfree on).

Had the issue on both crux and slackware, always when scrolling in firefox, but to be fair, that may just be coincidence because firefox is my most used app outside of emacs and anything in an xterm. Last time it happened I was scrolling linuxquestions.org, so it's not exactly a graphically intensive page.

It's definitely just the gpu/display hanging as I have found that I can:
magic-sysrq r and then blindly: ctrl-alt-f1, ctrl-alt-delete, which triggers init to "shutdown -r".