Re: i915 observations

[Mateusz Poszwa <old4%o2.pl@localhost>]

On Thu, Jul 21, 2022 at 10:51:15AM +0200, Frank Kardel wrote:
> Where do we collect i915 (-current) issues? We don't seem
> to have many PRs in that area. I have a data point with a
> Thinkpad T15p where i915 almost works but has flickering
> dark dashes and massively delayed keyboard input.
> Unfortunately I have to pass the notebook on to a
> college.

I believe I may have the same issue with ASUS EeeBox PC EB1037, which
I’m not going to part with any time soon, although I would describe
it differently. In my case, the dashes don’t flicker. I think the
image is updated through seemingly randomly placed short horizontal
segments. The less of the screen needs updating, the slower the
update becomes. Full-screen updates are devoid of such glitches.

I also wouldn’t call the keyboard input delayed. I would say
that visual effects of keyboard input usually were delayed due
to the fact that they tend to require just a small part of the
screen updated. This is most visible when logging in with xdm.

Once logged in, I have a clock displayed, which enforces an update
every second, which also updates some of the remaining dashes.
Eventuąlly, the image tends to converge to the intended one (except
maybe for the clock itself, which tends to lag behind all the time).

Perhaps such descriptions don’t illustrate the symptom well. I may
try to record a screencast to see if it captures the glitches.