Created attachment 176324 [details] Monitor EDID SUMMARY Screen brightness is too low even at max brightness when HDR is enabled. I don't have an exact value but, here is what I tried: 1. Windows (HDR on & off) -> can read the display content comfortably under sunlight 2. Plasma with HDR off -> can read the display content comfortably under sunlight 3. Plasma with HDR on -> can't read the display content even in a brightly lit room. I also tried HDR videos with MPV. 1. With HDR enabled, dark scenes are too dark with no details. 2. With HDR disabled, dark scenes are viewable 3. On windows, dark scenes are viewable with both HDR on or off ** When HDR is disabled in Plasma, I'm using the built-in color profile ** My GPU is intel UHD iGPU STEPS TO REPRODUCE 1. Enable HDR in settings 2. Set SDR brightness to maximum and brightness to maximum -> notice the max brightness 3. Disable HDR in settings 4. Set brightness to maximum -> notice the max brightness OBSERVED RESULT 1. Brightness when HDR enabled is too low. 2. HDR videos played in MPV with dark scenes look black. EXPECTED RESULT 1. Brightness with HDR enabled or disabled to be similar SOFTWARE/OS VERSIONS Windows: Version 24H2 (OS Build 26100.2454) Linux/KDE Plasma: Arch Linux KDE Plasma Version: 6.2.4 KDE Frameworks Version: 6.9.0 Qt Version: 6.8.0 ADDITIONAL INFORMATION I'm attaching my display EDID if that helps.
Please attach the output of > kscreen-doctor -o when HDR is enabled
(In reply to Zamundaaa from comment #1) > Please attach the output of > > kscreen-doctor -o > when HDR is enabled Here is the output with HDR enabled: Output: 1 eDP-1 enabled connected priority 1 Panel Modes: 1:2560x1600@240*! 2:2560x1600@60 3:1600x1200@60 4:1280x1024@60 5:1024x768@60 6:2560x1600@60 7:1920x1200@60 8:1280x800@60 9:2560x1440@60 10:1920x1080@60 11:1600x900@60 12:1368x768@60 13:1280x720@60 Geometry: 0,0 1707x1067 Scale: 1.5 Rotation: 1 Overscan: 0 Vrr: Never RgbRange: Automatic HDR: enabled SDR brightness: 1261 nits SDR gamut wideness: 100% Peak brightness: 1261 nits Max average brightness: 604 nits Min brightness: 0.0496 nits Wide Color Gamut: enabled ICC profile: none Color profile source: sRGB Brightness control: supported, set to 100%
hmm, that's weird. If you reduce the SDR brightness to something more normal (like 500 or 600 nits), does it get even dimmer, or does the display somehow compensate for the average brightness level?
Also, please attach the output of drm_info when HDR is enabled, I wonder what HDR metadata we're sending the screen
Created attachment 176703 [details] drm_info complete output (In reply to Zamundaaa from comment #3) > hmm, that's weird. If you reduce the SDR brightness to something more normal > (like 500 or 600 nits), does it get even dimmer, or does the display somehow > compensate for the average brightness level? I gets dimmer. SDR brightness range for me is 50 - 1261 nits. I tried in increments of 100 and I can see the brightness change (In reply to Zamundaaa from comment #4) > Also, please attach the output of drm_info when HDR is enabled, I wonder > what HDR metadata we're sending the screen Here is the HDR metadata section from drm_info: │ │ ├───"HDR_OUTPUT_METADATA": blob = 288 │ │ │ ├───Type: Static Metadata Type 1 │ │ │ ├───EOTF: SMPTE ST 2084 (PQ) │ │ │ ├───Display primaries: │ │ │ │ ├───Red: (0.6816, 0.3164) │ │ │ │ ├───Green: (0.2627, 0.6895) │ │ │ │ └───Blue: (0.1426, 0.0488) │ │ │ ├───White point: (0.3115, 0.3408) │ │ │ ├───Max display mastering luminance: 604 cd/m² │ │ │ ├───Min display mastering luminance: 0.0496 cd/m² │ │ │ ├───Max content light level: 604 cd/m² │ │ │ └───Max frame average light level: 604 cd/m² │ │ └───"vrr_capable" (immutable): range [0, 1] = 1 Added the complete output of drm_info as an attachment. Not sure but, shouldn't Max display mastering luminance be 1261?
> Not sure but, shouldn't Max display mastering luminance be 1261? In theory, yes. In practice, I had this very issue of my monitor being too dim until I set the max brightness to the max. average instead of the max. peak brightness... I see two reasons for why this could be happening: 1. your monitor takes issue with the HDR metadata we send it. If you use gamescope on a tty, you might be able to play with different HDR metdata to figure this one out. We should probably allow configuring the HDR metadata we send to the screen for testing such cases as well. 2. the Intel kernel driver is still broken when it comes to handling the Colorspace property, and your monitor is one of the many that don't actually enable HDR unless that works properly. If your screen has an OSD where it shows whether or not HDR is enabled, please check that, and if you have another device with an AMD or NVidia GPU, you could check with that as well. For testing 2, if you're willing to compile KWin, you could also try changing BT2020_RGB in https://invent.kde.org/plasma/kwin/-/blob/Plasma/6.2/src/backends/drm/drm_pipeline.cpp?ref_type=heads#L300 to BT2020_YCC
(In reply to Zamundaaa from comment #6) > 2. the Intel kernel driver is still broken when it comes to handling the > Colorspace property, and your monitor is one of the many that don't actually > enable HDR unless that works properly. If your screen has an OSD where it > shows whether or not HDR is enabled, please check that, and if you have > another device with an AMD or NVidia GPU, you could check with that as well. It's an laptop with hybrid GPU setup. So, there's no OSD to show if HDR is enabled. I do have a mux switch to connect the display to dGPU. Tried this and with Nvidia and it looks correct. I don't have a measuring device but, I used a lightmeter app on my phone to check the brightness on both intel (~200 lux) and nvidia (~600 lux). So, I guess it's an intel issue then. Happens with both i915 and xe drivers > For testing 2, if you're willing to compile KWin, you could also try > changing BT2020_RGB in > https://invent.kde.org/plasma/kwin/-/blob/Plasma/6.2/src/backends/drm/ > drm_pipeline.cpp?ref_type=heads#L300 to BT2020_YCC I think my screen doesn't support BT2020_YCC according to EDID. CE colorimetry data xvYCC601 support......... No xvYCC709 support......... No sYCC601 support.......... No AdobeYCC601 support...... No AdobeRGB support......... No BT2020CYCC support....... No BT2020YCC support........ No BT2020RGB support........ Yes Metadata profile flags... 0x80
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(In reply to Akhil K from comment #7) > > It's an laptop with hybrid GPU setup. So, there's no OSD to show if HDR is > enabled. I do have a mux switch to connect the display to dGPU. Tried this > and with Nvidia and it looks correct. > I don't have a measuring device but, I used a lightmeter app on my phone to > check the brightness on both intel (~200 lux) and nvidia (~600 lux). So, I > guess it's an intel issue then. Happens with both i915 and xe drivers > Looks like an Intel driver issue, so is it okay to close this?
Yeah, let's close it
I'm not very sure what's the root cause. But on GNOME I have a HDR Brightness (called Luminances in gdctl) slider, which at max kinda solves the low brightness problem for me... gdctl show: ``` ➜ ~ gdctl show Monitors: └──Monitor eDP-1 (Built-in display) ├──Vendor: BOE ├──Product: 0x0c8b ├──Serial: 0x00000068 ├──Current mode │ └──2560x1600@240.000+vrr └──Preferences: └──Luminances: ├──default ⇒ 100.0 (default) └──bt2100 ⇒ 190.0 (current) ```