Backlight control does not work properly on C67ML

[gerroon]

• KOReader version:
  koreader-nightly-20160624
• Device:
  C67ML

Issue

The backlight control works half baked

Steps to reproduce

Open the light settings and put a number. Wait for the light to change (which does not happen)

Changing the light level works after enabling and disabling the light. Basically KR changes the light setting but the setting is not applied right away. I have to disable and reenable (using the hardware button) to see the new screen light setting.

It seems to work better on my other android devices although the degree of the light setting is different on different models ( like amoled vs ips). The same number can mean different intensities on different devices.

thanks

[gerroon]

Hmmm

Something is wonky on my other android devices. It seems like when I set it the first time my screen goes black (on Amoled). And it crashes on Toggling. I will try to get a log later.

[chrox]

Could you adjust the light intensity with two-finger vertical swiping?

[gerroon]

@chrox

Swiping works but it is like the original post. I have to disable and enable the light via the hardware ey to see the actual change. When I do swiping, I see the numbers changing at the top with no real affect. I have to do hardware way of toggling to get the real light intensity to be shown on the device.

[gerroon]

I wonder if this is related to the refresh issues I reported earlier.
#1955

[gerroon]

This controls brightness fine
echo 100 >/sys/class/backlight/rk28_bl/brightness

Anyother method is not refreshing the brightness. I tried couple "lcd" brightness apps, they modify the brightness but the result is not visible right away, until I enable or disable the light or click on the tray bar

[houqp]

We control brightness through the standard android API. I think the other apps go with the same approach too. Are you saying writing to /sys/class/backlight/rk28_bl/brightness works without needing to toggle to refresh?

[gerroon]

@houqp

Yes that does not require a refresh. My gut feeling is that the Android brightness settings for the einks are different than the brightness settings for the tablets with the lcds naturally.

The apps that I tried for changing brightness for Android(including Koreader) fails to change the brightness or the frontlight right away on my C67ML (eink android device), some sort of manual refreshing is needed afterwards. The only app that was able to do was rootdim or using the method I described above.

[houqp]

Judging from the name rootdim, I bet it also write to the file directly like you did ;P

Looks like we need to make a special case for C67ML in the code. Are all ONYX BOOX readers based on android?

[gerroon]

@houqp

I am guessing that this might be an issue with all the EInk Android devices.

As far as I know Onyx makes Android devices though one of its models might be just a Linux based.

My device is rooted so if KR needs root permissions it is not a problem for me however I do not know how other people feel about it.

[verge-36]

Hello. I have a rooted NOOK Glowlight Plus, which is also an Android based E-Ink(Carta?) device. I don't think it is an issue with all eink android devices.
Two finger vertical scrolling isn't working for me(Usually crashes). But using Menu-Frontlight to apply screen brightness works fine.Screen usually goes black when i first set it, I tap once then it is fixed.I can change it with no black screen issue, no problems until i exit the app. Can normally change it after first black screen.
My device doesn't support full screen refresh with koreader. Maybe it is in some way related? I uploaded strace and logcat to a closed issue i opened(#2034) about this btw. Hope it can be easily implemented soon :D
--Sorry for bad english--

[gerroon]

I get the initial blackness with my all android devices (lcd and eink)

[Frenzie]

@gerroon Is this affected by #3319?

[gerroon]

The device was sold sometime ago ;)

[Frenzie]

I'll close it as lacking information then. ;-) (It just distracts otherwise.)