Intel GeminiLake corruption at top of screen caused by fbc
Submitted by Daniel Drake
Assigned to Intel GFX Bugs mailing list
Link to original bug (#108085)
On Intel GeminiLake platforms, a horizontal line of display corruption frequently appears at the top of the screen.
This seems to happen on every single GeminiLake platform that we try. Affected units include Asus E406MA and Acer Aspire XC-830.
We also have enough systems on hand to confidently say that it does not affect ApolloLake, KabyLake, CoffeeLake nor WhiskeyLake.
It is reproducible:
- On Fedora 28 with all updates (Linux 4.18, mesa-18.0) on both X and wayland.
- On Fedora 29 beta (Linux 4.18, mesa 18.2) with all updates, under wayland
- On Endless OS with Linux 4.19-rc5 and also on today's linux-next
Reproducer: at gdm, repeatedly click on the time/date to open and close the calendar several times.
Alternative reproducer, a bit harder: open terminal, run dmesg, maximize the terminal, then use two-finger scroll to quickly scroll up and down.
A video showing the problem under Endless. (note that Endless has modified gdm to eliminate time/date at the top, so I instead reproduce by opening and closing a menu repeatedly)
Another video showing that sometimes the corruption persists for a long time. It's a bit hard to see in the video, but I can move the mouse over the corrupted area and while the corruption persists underneath, the mouse cursor itself is rendered just fine.
I can't reproduce if I run with LIBGL_ALWAYS_SOFTWARE=1
When the corruption persists on screen, if I take a screenshot with "DISPLAY=:0 import -window root out.png", the captured output is fine (it does not show the corruption)
Please let me know how I can help debug further
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