Bug 500471 - Wayland display info is noisy but undescriptive
Summary: Wayland display info is noisy but undescriptive
Status: RESOLVED FIXED
Alias: None
Product: systemsettings
Classification: Applications
Component: kcm_kscreen (show other bugs)
Version: 6.3.1
Platform: Arch Linux Linux
: NOR minor
Target Milestone: ---
Assignee: kscreen-bugs-null@kde.org
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-02-20 16:13 UTC by gudvinr+kde
Modified: 2025-03-09 03:17 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed In: 6.3.3
Sentry Crash Report:


Attachments
wayland (51.92 KB, image/png)
2025-02-20 16:13 UTC, gudvinr+kde
Details
x11 (19.02 KB, image/png)
2025-02-20 16:13 UTC, gudvinr+kde
Details

Note You need to log in before you can comment on or make changes to this bug.
Description gudvinr+kde 2025-02-20 16:13:36 UTC
Created attachment 178643 [details]
wayland

SUMMARY

On wayland, you see display serial numbers in display settings.

That is way too much information when you don't have at least 2 of the same monitors.

And even if you do, how the heck would you determine which one is ASUS123/FAK3B88B and which is ASUS123/HU6E4SS? Serial number stickers are on the back and one of my monitor doesn't even have numbers from display settings on its sticker.

Better solution would be to use something you can easily check, like output name (HDMI-1, DP-2, etc).
Sure, it is still confusing if you have both connected to HDMI or DP. But it is not worse than gibberish serial numbers.

And most importantly, these serial numbers are not even needed if you have different displays. And on X11 it's exactly this. Display name is just the name.

STEPS TO REPRODUCE
1. Open display settings on wayland
2. Open display settings on x11

OBSERVED RESULT

Wayland contains more info but this information is just noise.

EXPECTED RESULT

No unnecessary gibberish.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.3.1
KDE Frameworks Version: 6.11.0
Qt Version: 6.8.2
Kernel Version: 6.13.2-arch1-1 (64-bit)
Graphics Platform: Wayland
Graphics Processor: AMD Radeon RX Vega M GL Graphics
Comment 1 gudvinr+kde 2025-02-20 16:13:55 UTC
Created attachment 178644 [details]
x11

For the comparison, what you see on x11
Comment 2 gudvinr+kde 2025-02-20 16:26:31 UTC
Interestingly, on X11 one display shows "Model" (BenQ PD2700U) and another one shows both manufacturer and the model (Dell Inc. DELL P2418D) while both fields are used on wayland.

Here's DDC:
   Mfg Id:               DEL
   Model:                DELL P2418D

   Mfg Id:               BNQ
   Model:                BenQ PD2700U

I'd assume that resolver used for wayland doesn't have mapping for "Mfg Id: BNQ" and just uses Id itself. And resolver on X11 skips unknown manufacturer.

Ideally, I'd perfect to just have what I have in "Model" in both cases but in reality it is likely that some manufacturers add the name in Model and some don't. Probably that might depend on many factors and even the same manufacturer might have different naming schemes.

There will be no ideal solution. But there should be some middle ground which will make names pretty but still descriptive. I guess telemetry could be used to gather this kind of data.
Comment 3 Bug Janitor Service 2025-03-06 00:49:15 UTC
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/7271
Comment 4 Oliver Beard 2025-03-06 16:15:12 UTC
Git commit be91df80ef44386f98a831a5f4dfdfd4a3b6e83e by Oliver Beard.
Committed on 06/03/2025 at 15:53.
Pushed by olib into branch 'master'.

utils/edid: Report monitor name without serial number
This fixes the use of a redundant serial number in both the KScreen KCM and the outputlocator effect. Logic already exists in both to insert the serial number when the manufacturer and model numbers are insufficent to disambiguate.

M  +1    -6    src/utils/edid.cpp

https://invent.kde.org/plasma/kwin/-/commit/be91df80ef44386f98a831a5f4dfdfd4a3b6e83e
Comment 5 Oliver Beard 2025-03-06 16:33:16 UTC
Git commit 63bd8c7d8ab5af70c8490c6e34e55ce4b0711bc3 by Oliver Beard.
Committed on 06/03/2025 at 16:33.
Pushed by olib into branch 'Plasma/6.3'.

utils/edid: Report monitor name without serial number
This fixes the use of a redundant serial number in both the KScreen KCM and the outputlocator effect. Logic already exists in both to insert the serial number when the manufacturer and model numbers are insufficent to disambiguate.


(cherry picked from commit be91df80ef44386f98a831a5f4dfdfd4a3b6e83e)

Co-authored-by: Oliver Beard <olib141@outlook.com>

M  +1    -6    src/utils/edid.cpp

https://invent.kde.org/plasma/kwin/-/commit/63bd8c7d8ab5af70c8490c6e34e55ce4b0711bc3
Comment 6 John 2025-03-08 11:29:34 UTC
I think the serial number should still be shown when there are multiple outputs with the same name / connector.
Comment 7 gudvinr+kde 2025-03-08 14:51:45 UTC
(In reply to John from comment #6)
> I think the serial number should still be shown when there are multiple
> outputs with the same name / connector.

What will you do with it? I honestly can't understand usefulness of this.

When you know which physical monitor correspond to its virtual counterpart, you don't need anything, not even a model.

Distinct names are needed when you don't know which one of these rectangles in KCM are "one of X monitors that are in front of me".

Imagine, you have serial numbers shown. Then what?
Would you move monitors around to see stickers on the back?
Would you go through every item in monitor's OSD to find its serial?

Not every monitor even have serial in OSD. There is no serial in OSD of both monitors that I currently have.

Serial number is useful for software because it is fairly unique. But it is the opposite of useful for human interactions.

If you have 2 monitors, you can just wiggle mouse around and it'd be quicker than comparing serial numbers.
And what will you do with 4, 6 monitors of the same model? More monitors you have, the higher chances that you bought the same model.

Inside "brightness and colour" applet it's even worse. You don't even have visual display arrangement to make a decision. And serial in the name won't help you. But this isn't about the applet, so it's not that relevant.
Comment 8 Oliver Beard 2025-03-09 03:17:35 UTC
(In reply to John from comment #6)
> I think the serial number should still be shown when there are multiple
> outputs with the same name / connector.

This is the default logic, it just never kicked in (to add the serial when needed for disambiguation) because the serial was already being added to the model name, making it unique.

But I've seen displays with the same serial, it's not reliable for this, so I do intend to make disambiguation better in the future by just reporting the index of the displays.