Bug 435103 - Using an interlaced resolution hangs the desktop
Summary: Using an interlaced resolution hangs the desktop
Status: RESOLVED DOWNSTREAM
Alias: None
Product: kwin
Classification: Plasma
Component: compositing (show other bugs)
Version: 5.21.3
Platform: Manjaro Linux
: NOR grave
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-03-29 10:23 UTC by Alberto Salvia Novella
Modified: 2021-03-30 09:05 UTC (History)
1 user (show)

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Description Alberto Salvia Novella 2021-03-29 10:23:56 UTC
Okay, so this is weird.

After a few minutes of being logged in the entire desktop hangs only with this particular model of Telefunken TV (TLFK22LEDPVR1), and only if composition is on.

I have tried it with another two displays with the same native resolution and refresh rate, and there was no problem.
Comment 1 Alberto Salvia Novella 2021-03-29 10:27:01 UTC
- Radeon HD5870
- plasma 5.21.3
- mesa 20.3.4
- xorg-server 1.20.10
- linux 5.10
Comment 2 Alberto Salvia Novella 2021-03-29 10:36:07 UTC
It only happens on xorg, but not on wayland.
Comment 3 Alberto Salvia Novella 2021-03-29 13:06:42 UTC
I'm seeing it also without composition, but there it's rare to happen.

I also figured out that there's a difference between the screens that don't exhibit the problem and this one. This one uses an interlaced signal.
Comment 4 David Edmundson 2021-03-29 13:42:23 UTC
when you say "the entire desktop" are you able to move the mouse?
Comment 5 Alberto Salvia Novella 2021-03-29 14:07:11 UTC
It varies. Sometimes only the panel becomes unresponsive, others all the content in the screen. If there is music playing in the background it continues playing normally.

I confirm you that when using 720p on this screen the desktop doesn't freeze, so this is due to using an interlaced signal.
Comment 6 Vlad Zahorodnii 2021-03-29 16:19:48 UTC
(In reply to Alberto Salvia Novella from comment #3)
> I'm seeing it also without composition, but there it's rare to happen.
If that's the case, it indicates that the issue lies either in Xorg or the driver.

> I also figured out that there's a difference between the screens that don't
> exhibit the problem and this one. This one uses an interlaced signal.
Comment 7 Alberto Salvia Novella 2021-03-29 16:35:30 UTC
Any idea how to figure which subsystem is to blame?

I don't see anything useful in the system logs.
Comment 8 Alberto Salvia Novella 2021-03-30 09:05:02 UTC
I have tested this only happens with radeon hardware, so that driver is the one to blame.