Virtual console does not redraw

[johalun]

Typed characters does not show up on screen until one switch VT back and forth ones. Only occurs on rare hardware or on rare occasion..

[valpackett]

When? If it's after switching from a graphical display server, it might be just the vt being left in the mode that doesn't echo..

[johalun]

Apparently the only variable is drm-v4.16 (OK) vs drm-v5.0 (has this bug). I suspect the drm fb helper.

[johalun]

This happens before even starting X, when loading drm driver at virtual console.

[valpackett]

I have a Kaby Lake device now, am seeing this. Switching to a new vt does redraw the screen..

[valpackett]

Interesting: looks like this maybe does not happen with fastboot enabled? (need to retest, I'm actually not sure)

(But fastboot breaks backlight on my new laptop (on Linux too, it's a known thing) haha)

and sometimes quitting from a GUI display server restores refresh too

[javashin]

fastboot is fixed on 5.2.X
the backlight issue

[javashin]

also mpv cant play any video on the KMS Drm console its useless too slow , maybe is this related ?

[valpackett]

no, this is about vt (virtual terminal), userspace applications that use DRM are fine

[javashin]

yes on Vt kms drm >> after load kldload i915kms and use on the same console tty vt no X > mpv -vo=drm foo.mp4 = very slow reproduction of video media , too slow means unusable. unwatchable

[wulf7]

Setting compat.linuxkpi.i915_enable_psr boot loader parameter to 0 workarounds at least "VT redraw" issue to me.
fastboot does not work with suspend/resume on my laptop.
P.S. 'does not work' means VT redraw is stopped after wakeup