Bug 460728 - On X11, 1920x1080 resolution setting defaults to interlaced 1080i mode on TV screen, not 1080p
Summary: On X11, 1920x1080 resolution setting defaults to interlaced 1080i mode on TV ...
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: multi-screen (show other bugs)
Version: 5.25.5
Platform: Debian stable Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: multiscreen, X11-only
Depends on:
Blocks:
 
Reported: 2022-10-19 19:32 UTC by Mahe
Modified: 2025-02-24 17:58 UTC (History)
6 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
KScreen-Doctor output requested by Nate (16.59 KB, text/plain)
2022-11-10 20:02 UTC, Mel
Details
Output of "kscreen-doctor -o" for Sony KD-49XH9505 (connected as HDMI-1) (1.15 KB, text/plain)
2022-11-10 21:58 UTC, Mahe
Details
Output of "kscreen-console bug" for Sony KD-49XH9505 (connected as HDMI-1) (17.13 KB, text/plain)
2022-11-10 21:59 UTC, Mahe
Details

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Description Mahe 2022-10-19 19:32:26 UTC
SUMMARY
Selecting a resolution of 1920x1080 for a connected TV screen that also supports 1080i (interlaced) will lead to the interlaced mode being activated and there seems to be no way of selecting the genuine 1080p resolution in KDE/Plasma.

STEPS TO REPRODUCE
1. Attach TV screen as a secondary monitor to the graphics card.
2. Go into control center's display settings. 
3. Set the TV screen to a resolution of "1920x1080" and a refresh rate of "60 Hz".

OBSERVED RESULT
The resolution is actually set to 1080i (interlaced mode) instead of full 1080p despite the TV device being capable of the latter. That the mode is set to 1080i can be confirmed both with xrandr as well as on the TV device information menu itself.
Relevant xrandr output after setting up the TV screen:

HDMI-1 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 1085mm x 610mm
   3840x2160     30.00 +  25.00    24.00    29.97    23.98  
   4096x2160     24.00    23.98  
   1920x1080     60.00    50.00    59.94    30.00    24.00    29.97    23.98  
   1920x1080i    60.00*   50.00    59.94  
(output truncated, note the asterisk at the 1080i 60Hz mode)

Setting the mode to genuine 1080p using "xrandr --output HDMI-1 --mode 1920x1080" works but gets reset to 1080i by KScreen once the TV screen is disconnected and reconnected again.

EXPECTED RESULT
Either
a) the resolution list should offer both "1920x1080" as well as "1920x1080i" (interlaced) to be selected individually
or
b) selecting "1920x1080" should apply the non-interlaced 1080p mode (in case 1080i is not supposed to be offered at all).

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.2
Debian GNU/Linux 11, Kernel 5.10.0

ADDITIONAL INFORMATION
Main screen is a 1080p LCD plugged in via DVI. The affected TV is a SONY KD-49XH9505 plugged in via HDMI.
Both are connected to an Intel UHD Graphics 630 iGPU directly on the motherboard.
This report applies to X11, I haven't tested Wayland yet.
Comment 1 Bug Janitor Service 2022-10-19 19:34:16 UTC
Thank you for the bug report!

Please note that Plasma 5.25.5 is not supported for much longer by KDE; supported versions are 5.24, and 5.26 or newer.

If at all possible please upgrade to a supported version and verify that the bug is still happening there.
Comment 2 Mel 2022-10-26 19:23:08 UTC
Hello, I also have this issue with my SONY X900F, connected through HDMI via a DisplayPort to HDMI adapter. I can set the correct 1920x1080 mode through Kscreen-doctor, however KDE seems to reset it if the display goes to sleep, and on login. 

In Kscreen-doctor, the last output for 1920x1080@60 is the one that KDE seems to use, and is also the interlaced option. The first entry is the one I use, which works correctly.

Interestingly Kscreen-doctor does not specify interlaced outputs, instead it has repeated 1920x1080@60 modes listed. I also looked around in KScreen's code and didn't find any code relating to handling or ignoring interlaced modes. 


System Info:
Operating System: KDE neon 5.26
KDE Plasma Version: 5.26.1
KDE Frameworks Version: 5.99.0
Qt Version: 5.15.6
Kernel Version: 5.15.0-52-generic (64-bit)
Graphics Platform: Wayland
Processors: 6 x Intel Core i5-9500 CPU @ 3.00GHz
Memory: 15.4 GiB of RAM
Graphics Processor: Mesa Intel UHD Graphics 630
Manufacturer: Dell Inc.
Product Names OptiPlex 7070

(I had to OCR the system info and correct mistakes, as I can't easily send text from my living room pc atm. So apologies for any minor spelling errors.)
Comment 3 Nate Graham 2022-11-10 19:46:05 UTC
Can you attach the output of both `kscreen-doctor -o` and kscreen-console bug`  when the affected TV is connected and inappropriately using the 1080pi resolution? Thanks!
Comment 4 Mel 2022-11-10 20:02:28 UTC
Created attachment 153647 [details]
KScreen-Doctor output requested by Nate

Here's the attached Kscreen-doctor output from both -o and -j. 

The currently selected mode (#10) is interlaced output. I have a script that I run to automatically set the mode to #7 which is progressive output. (1080p). 

As you can see in kscreen-doctor's json output, there's no indicator for interlaced vs progressive. And from my brief poking around at the code, I think it doesn't even consider interlaced as a concept for automatic resolution selecting / UI list. 

Note: I'm not using 4k, since the cable doesn't support 4k@60. And the onboard graphics isn't really up to the task either.

Let me know if you need anymore information!

Cheers,
Mel
Comment 5 Mahe 2022-11-10 21:58:49 UTC
Created attachment 153652 [details]
Output of "kscreen-doctor -o" for Sony KD-49XH9505 (connected as HDMI-1)
Comment 6 Mahe 2022-11-10 21:59:32 UTC
Created attachment 153653 [details]
Output of "kscreen-console bug" for Sony KD-49XH9505 (connected as HDMI-1)
Comment 7 Nate Graham 2022-11-14 18:51:25 UTC
Thanks. I think this is a KWin bug; moving there.

Any chance you could give it a try on Wayland and see if it works as expected there?
Comment 8 Linus Kardell 2023-09-07 08:18:07 UTC
I have the same problem on OpenSUSE Leap 15.5, with Plasma 5.27.4. Primary GPU is a Radeon RX 6500 XT, but the monitor in question is connecting is connected to a GeForce GT 1030 DDR4 (nouveau) using Prime display offload. The problem does not occur on Wayland (it still doesn't let you choose between progressive and interlaced, but at least Plasma Wayland doesn't default to interlaced).
Comment 9 TraceyC 2025-02-24 17:58:52 UTC
Adding the x11-only keyword