Brightness annoyingly adjusts slightly to cater for what's on screen - AKA Dynamic Contrast

[ZimbiX]

As noticed by @ksandom in his blog post, the Astro has some sort of dynamic contrast enabled.

From Discord:

ZimbiX: I have noticed, as your article mentions, that even with auto-brightness turned off, something is slightly adjusting the brightness, seemingly based on the brightness of what's bring displayed. Which sounds a lot like the dynamic contrast feature I've seen before somewhere, which was just a dodgy way for the manufacturer to increase the contrast ratio spec. I find it just barely noticeable at full brightness switching back and forth between a white screen in Chrome and a dark but not entirely black screen in Termux - e.g. after switching to Termux, the screen dims a couple of steps over like 5 seconds

Device: Astro Slide Android build number: Astro-11.0-Planet-05182022-V01 Custom build number: alps-mp-r0.mp1-V8.132_haocheng.r0mp1.k61v1.64.bsp_P20

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I was just having a flick through the commits tree of Planet kernels and came across this commit for the Gemini kernel: https://github.com/lukefor/gemini-linux-kernel-3.18/commit/a71d4a9ab155f02d895bec69b0f2553515a809b2

It looks like that disables dynamic contrast, and that it's still applicable to the Astro kernel! :grinning: (this defconfig file is the one used for the Astro)

I haven't given it a go yet, but am keen to see if this patch fixes it.

Edit: Hmm, I'm really fighting the bot with the labels on this one!

[ZimbiX]

Actually, this might not be so simple (I believe the broken OESF link in the commit message should go here) - but perhaps the resulting sleep problem only affects Linux, not Android..