Mediumly trivial.

Out of curiosity, what's your use case for changing at runtime?

(In reply to David Edmundson from comment #1)
> Mediumly trivial.
> 
> Out of curiosity, what's your use case for changing at runtime?

I switch to HDR for the few videos and games which support it. Otherwise, I use SDR for accurate colours that aren't oversaturated, unlocks more monitor options, and allows use of an ICC profile. Kscreen-docotr's "Wide Color Gamut" setting only seems to have any effect in SDR as well. 

Disabled settings seems to be a fairly common issue with HDR monitors for PCs. My display disables gamma, colour temperature, contrast, brightness, and etc. when switched to HDR mode. Here are some examples of three large brands who configured their firmware to lock display settings while HDR is enabled: 

LG https://www.reddit.com/r/Monitors/comments/1ij3sxf/i_just_bought_this_monitor_but_these_options_are/mbaxnf1/

ASUS https://rog-forum.asus.com/t5/gaming-monitors/pg32ucdm-settings-locked-in-hdr-mode-help/td-p/1003728

Acer https://community.acer.com/en/discussion/646047/acer-predator-xb323u-gxbmiiphzx-32-settings-locked-in-srgb-and-hdr-plus-heat-in-hdr

One last link that perfectly sums up the issue with HDR monitors:

You lose access to many monitor settings

Nearly all monitors we’ve tested and used have very restrictive OSD settings and options when running in HDR mode. When an HDR signal is detected, they switch to their designated HDR preset mode which is set up to handle the different gamma curve and tone mapping, and correctly handle HDR brightness, colours and other aspects of the content. These modes nearly always have a very locked down group of settings in the OSD menu. Normally common settings like brightness and contrast are locked, colour settings, RGB channels, gamma etc. This is generally ok for HDR content for which these modes have been configured (or should have been if it’s a decent screen), but you are at the mercy of the manufacturer, with no ability to make personal adjustments. This is probably ok for handling HDR content, but when you’re actually viewing SDR content like your Windows desktop you probably want better control over the screen’s settings.

Being able to adjust the preset mode, colour temp setting, RGB channels, gamma setting etc are all very useful in adjusting your screen to your liking and room conditions. You can’t do any of this really if you run the screen in HDR mode all the time, and this is another reason why you are better off only enabling HDR mode when you want to view HDR content.

https://tftcentral.co.uk/articles/heres-why-you-should-only-enable-hdr-mode-on-your-pc-when-you-are-viewing-hdr-content

(In reply to Real Name Here from comment #2)
> I switch to HDR for the few videos and games which support it. Otherwise, I
> use SDR for accurate colours that aren't oversaturated, unlocks more monitor
> options, and allows use of an ICC profile. Kscreen-docotr's "Wide Color
> Gamut" setting only seems to have any effect in SDR as well. 
Colors should definitely not be oversaturated in HDR mode, and you wide color gamut on/off should have SDR apps look the same in both SDR and HDR display modes.
What you're seeing is almost certainly a driver bug, please report that to your GPU vendor!

If working around driver bugs is the biggest reason for adding such a shortcut by default, I'd prefer not do it. If you can't leave HDR on all the time, something's broken and needs to be properly fixed - and adding a script yourself is fine for workarounds.

> Disabled settings seems to be a fairly common issue with HDR monitors for
> PCs. My display disables gamma, colour temperature, contrast, brightness,
> and etc. when switched to HDR mode. Here are some examples of three large
> brands who configured their firmware to lock display settings while HDR is
> enabled: 
Yes, that's very common, somehow understanding how to properly present content is a rarity among display manufacturers.

However, you shouldn't need to change display modes to work around that - we already have brightness controls, and adding more settings is possible and already planned. If you have the need for any specific one(s), please make a separate bug report about it, so we can prioritize.

(In reply to Zamundaaa from comment #4)
> Colors should definitely not be oversaturated in HDR mode, and you wide
> color gamut on/off should have SDR apps look the same in both SDR and HDR
> display modes.
> What you're seeing is almost certainly a driver bug, please report that to
> your GPU vendor!

I've tested wide color gamut with Intel's UHD Graphics 770 and Nvidia 4000 series GPU, kernel's i915 and nvidia open drivers respectively. Neither are impacted by toggling wcg when HDR is enabled. With integrated GPU enabled, kinfo reports: 

Graphics Processor 1: Mesa Intel® Graphics
Graphics Processor 2: llvmpipe

Without the integrated GPU:

Graphics Processor: NVIDIA GeForce RTX 4090/PCIe/SSE2

Does the above still suggest a driver issue?

What GPU is the display actually connected to? You can check with drm_info.

Generally I would still assume that it is a driver issue, or maybe a display quirk the drivers have to add. FWIW I know for certain that Intel's handling of the "Colorspace" property / wcg is still broken and yields wrong results in many cases.

Could you clarify what you mean with "neither are impacted by toggling wcg" though? Do they blank (turn off then on again), flicker or do anything visible at all when you toggle it?

(In reply to Zamundaaa from comment #6)
> What GPU is the display actually connected to? You can check with drm_info.

For the first test, I disabled the NVIDIA driver then switched my display's input to a second HDMI 2.1 port connected to the Intel GPU. Afterwards, I disabled the Intel driver then switched my display's input to the first HDMI 2.1 port, which is connected to my NVIDIA GPU. I also tested DisplayPort 1.4 with both GPUs as well.

Also, I have access to an AMD 7000 series card. Please let me know any and all tests you'd like for me to run before I try that card as I won't be able to test it again.

> Could you clarify what you mean with "neither are impacted by toggling wcg"
> though? Do they blank (turn off then on again), flicker or do anything
> visible at all when you toggle it?

The monitor turns black for ~3 seconds, but unlike SDR mode the colours are not clamped to sRGB thus remain saturated.

Thank you for the WCG feature, by the way! It works so well in SDR mode that I no longer need an ICC profile.

Having tested integrated Intel and external NVIDIA GPUs, I'm curious for which drivers is the wide color gamut confirmed to work?

> The monitor turns black for ~3 seconds, but unlike SDR mode the colours are not clamped to sRGB thus remain saturated.
sRGB values don't need clamping.

It sounds like maybe your monitor is doing something wrong, color intensity should really not change at all. Does the monitor have any picture settings that you can access in HDR mode? Mine has some color profile options that cause a similar issue if it's used (though thankfully it's not the default).

(In reply to Real Name Here from comment #8)
> Having tested integrated Intel and external NVIDIA GPUs, I'm curious for
> which drivers is the wide color gamut confirmed to work?
Newer AMD and NVidia cards are known to work properly. So if it doesn't work with either of them, there's probably another issue.

Hi,


i also would like a shortcut for enabling/disabling HDR.
As there is none, i simply created a script which enables/disables hdr and adjusts brightness with kscreen commands.

My reasoning behind that is that:

- Due to recent changes in kwin, i have to push display brightness to 100% in HDR to get a reasonable hdr picture. That was not the case in the past (which i heavily preferred), but that discussion is already over
- I do not want to drive the display at that level for normal desktop usage, i prefer i way lower brightness there
- Immo abl kicks in more agressivly in hdr mode

-> Using hdr for normal desktop usage is a nogo for me.

Br

(In reply to bugreports61 from comment #10)
> - Due to recent changes in kwin, i have to push display brightness to 100%
> in HDR to get a reasonable hdr picture. That was not the case in the past
> (which i heavily preferred), but that discussion is already over
> - I do not want to drive the display at that level for normal desktop usage,
> i prefer i way lower brightness there
> 
> -> Using hdr for normal desktop usage is a nogo for me.

Yeah I agree - no desktop specific / SDR brightness setting is pretty insane to me, I made an account to voice about this issue a while ago and it doesn't seem like there's a middle ground being made here.

A toggle for HDR would atleast be ... acceptable.

I'm just a user. I don't want to blind myself during normal desktop use just to get accurate HDR or something, I'm still not entirely sure why "SDR Brightness" is gone. Personally I just turned off HDR and forgot about it because it's too much hassle.