NanoPi R5C HDMI to TV, purple/green display tint after some time with TV off

Creating a bug report/issue

Required Information

  • DietPi version | 8.16.2
  • Distro version | bookworm
  • Kernel version | Linux dietpi-r5c-1 5.10.110 #1 SMP Tue Mar 14 21:42:07 CST 2023 aarch64
  • GNU/Linux- Architecture | arm64
  • SBC model | NanoPi R5C
  • Power supply used | Raspberry Pi USB C power supply
  • SD card used | n/a (running on internal eMMC storage)

Additional Information (if applicable)

  • Software title | MATE desktop (also observed using LXDE)
  • Was the software title installed freshly or updated/migrated? fresh install
  • Can this issue be replicated on a fresh installation of DietPi? yes (have also observed using current bullseye release)
    ← If you sent a “dietpi-bugreport”, please paste the ID here →
  • Bug report ID | echo $G_HW_UUID

Steps to reproduce

  1. startup NanoPi R5C with HDMI output to (Samsung) TV, run MATE desktop … colors are as expected
  2. power off TV with R5C still running … wait for some time (not sure how long, but it requires waiting extended time)
  3. power TV back on … MATE desktop and any apps now show with purple/green tint

Expected behaviour

  • Display color should remain unchanged (RGB?)

Actual behaviour

  • Display color format changes

Extra details

  • once color format changes, it can be reset to RGB manually using xrandr or by restarting the R5C … would be better to have a config option to avoid/prevent

@MichaIng could you have a look pls.

Interesting, sounds similar to what @StephanStS observed on the VisionFive 2. Probably an issue with X11 in combination with the hardware if the plain console colours remain correct.

How did you exactly set it via xrandr? I guess there is an xorg.conf setting we can try.

Also we should try to replicate it on NanoPi R5S (these we have).

when the display tint changes, the following command got it back to normal

xrandr --output HDMI-1 --set "color_format" "rgb"

this just happens to be the first thing i tried that made a difference, so likely there’s a better way

(i’ve also seen the colors look as they should after powerup when “color_format” is listed as “ycbcr444”)

also, is HDMI out a relatively new thing for NanoPi devices? looks like everything on the R5C is software/CPU driven at this point, no graphics hardware acceleration … in addition to the item reported above, I’m able to help with other testing on the R5C

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