Database Users

[FIX] Yoga tablet 2 10" display sharpness fix (UPDATE for Lollipop)

Why Yoga tablet 2 screen looks so blurred and sharpened at the same time
Have you been wondering why your screen on the 10" Yoga tablet 2 with KitKat doesn't look really crisp even with some obvious sharpening applied? Here is why!
Lenovo screwed up twice!
1. Blur filter is applied. (KitKat ONLY) The BIOS/bootloader defines wrong display resolution. The Intel graphics driver (i915) gets confused and switches on panel fitting which includes a blur filter (fuzzy filter). Normally this is used if the display resolution is different from the frame buffer resolution to scale the image. Here the device just scales 1:1 and applies the filter. Luckily the driver is open source and it turns out there is a way to overwrite this feature No longer true for Lollipop. Thanks Lenovo
2. Sharpen filter is applied. (KitKat and Lollipop) The panel is not programmed correctly. When disabling the CABC feature (/sys/lcd_panel/cabc_onoff) the sharpening effect is gone. But CABC should have nothing to do with sharpen. Unfortunately the specs of the display (AUO B101UAN01.E) are not public so I cannot verify if the correct MIPI DSI commands are sent to the panel.
So our display is softened then sharpened again! What a waste!
Both workarounds are only temporary. After each screen off/screen on sequence the old values are restored by the system. So we need an app which sets the values after the screen is switched on. Or a new kernel. Or Lenovo cares to fix it in a future release
Fix (Root partially required)
I wrote an app which can disable CABC / sharpness filter (requires ROOT) and can disable the blur filter (KitKat, no root required) . Of course I am not held responsible if you brick or burn your tablet. I tested this on my 1050F with rooted firmware S000143_150105.
1. Copy app to device and install
2. Start app and select your setting
3. The settings may apply only after switching screen off and on again.
Source on Github:
http://github.com/Matshias/yoga2sharpness
Bugs / issues
- may not work directly after reboot, only after screen on/off
- fullscreen video may switch on CABC/sharpness filter again
Any suggestions? I'd be really happy if you could test and report
Cheers!
Matt
Update Jan 21
make more reliable and add complete source
Update Jan 26
Reliable implementation as app which automates this process.
Update Jan 30
new version 1.1 (please uninstall old version!):
- add option to start at boot and enable/disable applying the settings at screen on for manual operation
- add little delay after screen on for more reliable operation
- app should be harder to kill by the system
Update Feb 2
new version 1.1.1:
- Fix occasional reboot issue when using the setting on display on. Turns out Android sends screen on broadcasts sometimes even if the display is off. This causes a crash if the filter settings are applied.
Update Feb 11
new version 1.1.2 (please uninstall old version):
- hopefully ultimately fix reboot issues by using different method to start on boot
Update Apr 30
tested with new firmware S000198_150422. Same as before. Lenovo has not fixed the issue, but the app works like before
Update June 3
New version 1.1.3:
- fix full screen video playback re-enabling CABC/sharpness filter. As for CABC itself root is required.
Update June 17
Update for Lollipop version 1.2.0:
- blur filter disable no longer needed
- sharpness filter is still present. If root becomes available for Lollipop this should work there too
Update June 19
Fix for rooted Lollipop - version 1.2.1:
- the mechanism for sharpness filter disable from 1.2.0 didn't work, probably due to SE Linux restrictions

Matshias, you are a legend!
I bought a Yoga 2 10" a couple of weeks ago and the odd blurred and sharpened effect ruins what is otherwise a great little tablet. I'd always suspected it was some kind of odd scaling issue, but I haven't had time or sufficient Android knowledge (or root access on my device) to properly investigate it, beyond making up some test images with alternate 1 pixel wide black/white lines - which were rendering as grey on the Yoga 2.
I had a support ticket raised with Lenovo about the issue, so I've referred them to this post and one on the Lenovo Community forums.
Thanks for your hard work, hopefully Lenovo will implement the fix in a software update soon!
Cheers,
Richard

Thank you!
matshias: Thank you.
The blur filter disable makes a HUGE difference. I really appreciate you taking the time to post your results, hopefully Lenovo will take note and implement a permanent fix.

workes
Hi!
I have just started using your app with the latest firmware on a 1050L.
0) Unrooted device
1) installed your app and applied the non-root part of the fix - worked after screen on/off
2) rooted device with temporary cwm solution from this parent thread (- which worked as well)
3) applied the root-required part of the fix from your app - works as well
Thank you for this!

Great great great! Like the others here I was looking for a solution to this Problem since I bought the tablet.
I am really satisfied with your APP, now everything is way sharper.
BUT: When I test the screens resolution with a screen test APP, only the horizontal ( long sides) resolution seems to be right now. The vertical resolution (short sides) is still just grey, when testing single pixel lines.
Do you have the same Problem, what could cause this?

fanatictentacle said:
Great great great! Like the others here I was looking for a solution to this Problem since I bought the tablet.
I am really satisfied with your APP, now everything is way sharper.
BUT: When I test the screens resolution with a screen test APP, only the horizontal ( long sides) resolution seems to be right now. The vertical resolution (short sides) is still just grey, when testing single pixel lines.
Do you have the same Problem, what could cause this?
Click to expand...
Click to collapse
I see the same if the sharpness filter/CABC is still switched on. If you have root then try disabling the sharpness filter as well and then the screen test look fine. Obviously the sharpness filter in the panel is not uniform in all directions and seems to prefer horizontal resolution (in landscape mode).

Thanks again for the advice!
I just had to enable root, really cant look at that horrid screen anymore! But now it really looks as sharp as an 240ppi Display should look like!

problem
After installing the app I have problems.
In 10 minutes my tablet rebooted 3 times . Android not asked to reboot.
It was crash of sistem. My system is rooted.
After uninstalling I had no problems.
Regurds

Yosef said:
After installing the app I have problems.
In 10 minutes my tablet rebooted 3 times . Android not asked to reboot.
It was crash of sistem. My system is rooted.
After uninstalling I had no problems.
Regurds
Click to expand...
Click to collapse
Did you use the start on boot feature? This might cause it. I uploaded new version 1.1.2 which should fix that problem. Let me know if it works for you.

this is a fantastic fix, one that Lenovo should have implemented themselves
actually when i just got the tablet over christmas, it was running older firmware in which the blur filter was actually not enabled. yes i now realize the text was "over sharp" but it was clear, and what i expected for the price (i.e. not double the price for a galaxy tab S) but i was fine with the sharpness, it looked good, and the tablet otherwise suits my needs perfectly, and gotta love that built in stand. i didn't even know what people meant about the image quality, considering the mid-range target audience of the tablet.
anyway, i recently got the OTA firmware update to the current S000143_150105 and that's when it messed everything up. it enabled the blur filter, and it looked HORRIBLE. i tried to accept it because at 1 ft from the tablet, the text actually looked all right, perhaps even a slight improvement because it was slightly softer. but the blur filter is applied to EVERYTHING, so all the images and everything on the screen was blurred....it was like looking at an HD monitor with a state of the art GeForce video card but using the standard windows video drivers...everything stretched and totally blurry.
this is a great fix, i don't have my tablet rooted and don't want to take the potential battery hit to disable the sharpening filter (since i think it looks good just with the blur filter disabled). it might be in my head though, but i feel like the system is a little more sluggish...maybe due to the update, maybe because of this (great) app...i wish lenovo would fix this, seems easy enough. sours me to an otherwise great tablet for the price.
speaking of battery, i noticed in the last day after installing the fix that my tablet powered off sometime during the day, and when i restarted, the battery had drained about 30%. and it continued to drain faster than before. i previously got well over 10 hours of usage time playing movies and web browsing, in addition to up to several days of standby....today i had to charge it within 24 hours and only got about 7 hours use time and 13 hours standby...any chance it's related to the fix, or has anyone experienced it after the firmware update?

@digitalatlas: Thanks for testing the app.
Regarding your observations, I don't think sluggishness can be attributed to the app. After all it doesn't do much. Only when the screen is switched on or you manually start the app it changes the kernel setting. So it really shouldn't have any impact on performance.
The battery life should also not be affected by the app itself. It does not have any background tasks other than the kernel setting mentioned above and it shouldn't wake up the device as well. Although I saw occasionally that my app gets informed that the screen was switched on even though the screen was not switched on. That caused some reboot issues. But that was fixed with version 1.1.1 and 1.1.2 and I didn't see a reboot since I use 1.1.2. Also there are reports of hangs/reboots by other users unrelated to my app. Anyways it might be the case that changing the kernel setting has some other effect on the hardware, kernel and battery life. According to Intel documentation the filter is not meant to be switched on or off while the display is active. However, it is the only time it is possible to change it in our system. So to be sure we have to test and disable/uninstall the app and see if the battery life improves.
Hopefully Lenovo fixes this with an upcoming update!

Thanks!
Just got this tablet in the mail today and was disappointed by its display. So grateful for your fix, its like night and day with the blur gone. Guess I have a good reason to root now to get rid of the sharpness too. Mind me asking what method you used to root for this firmware?

Falv said:
Just got this tablet in the mail today and was disappointed by its display. So grateful for your fix, its like night and day with the blur gone. Guess I have a good reason to root now to get rid of the sharpness too. Mind me asking what method you used to root for this firmware?
Click to expand...
Click to collapse
I used the temporary CWM method [GUIDE] CWM & Root Lenovo Yoga 2 (8/10/13)
It is easy enough and works fine, but keep in mind that there might be issues with OTAs.

I'll keep track of the battery over the next little while, hopefully it was just an aberration that first charge. I'm getting better results with this second charge since the update and your fix.
Could you or someone post a picture shoeing the effect of turning the sharpening filter off? Might help some of us decide it rooting is in fact worthwhile. Thanks!

digitalatlas said:
I'll keep track of the battery over the next little while, hopefully it was just an aberration that first charge. I'm getting better results with this second charge since the update and your fix.
Could you or someone post a picture shoeing the effect of turning the sharpening filter off? Might help some of us decide it rooting is in fact worthwhile. Thanks!
Click to expand...
Click to collapse
I tried taking pictures but it doesn't really show the effect. Instead I made two screenshots and recreated the filter with GIMP. It should be very close to what the panel does.

Does anybody have any info from Lenovo? I think that this is preposterous! How can someone do that and have it go through testing? Unless there were no tests at all.
Buying Lenovo was a mistake.

v1.2 tested on my new 1050F. Awesome. I was disapointed by the screen but now it's perfect. Thank you so much to have done this patch!

+1
AMAZING PICTURE QUALITY!!.
Without blur picture is good, but witchout blur and sharpness image quality is FU…NG AWSOME!!
THANKS!!!!!

saupiquet said:
v1.2 tested on my new 1050F. Awesome. I was disapointed by the screen but now it's perfect. Thank you so much to have done this patch!
Click to expand...
Click to collapse
+1
Great app, thank you

Are you all running this with rooted devices? Mine is not yet rooted but notice a big difference with this app. How much better is it if I was to root the device? Thank you so much for this fix. I recieved my tablet today and was very disappointed with the display.

Screen flickering on my OP2

Out of nowhere, my phone's screen has tarted to flicker. The brightness flickers and is very distracting. I've already tried to flash the latest OxygenOS available, but it hasn't worked.
Thing is, it flickers in both OOS and TWRP but it doesn't when booting up and in the bootloader.
Is it a hardware issue or there's a software fix?

kami_sama said:
Out of nowhere, my phone's screen has tarted to flicker. The brightness flickers and is very distracting. I've already tried to flash the latest OxygenOS available, but it hasn't worked.
Thing is, it flickers in both OOS and TWRP but it doesn't when booting up and in the bootloader.
Is it a hardware issue or there's a software fix?
Click to expand...
Click to collapse
I've the same issue...out of the blue it started flickerin and is very annoying...half of the screen (dx side) is slightly more yellow...Have you found any fix for this?

afarnedi said:
I've the same issue...out of the blue it started flickerin and is very annoying...half of the screen (dx side) is slightly more yellow...Have you found any fix for this?
Click to expand...
Click to collapse
Nope, in the end I had to RMA the phone.
I had to go through the hops from support, but they were certain it was a hardware fault, I had it fixed at no cost.

There can be two things, one's Adaptive Brightness which usually does that, check if you have it enabled, disable it.
Second thing can be CABC (Content Adaptive Backlight Control) which works as opt's lcd throttler. It throttles, i.e. puts the brightness to a bare minimum when the temperature of the screen exceeds a particular value.
Now disabling this isn't very productive and/or practical. But if you want it disabled you can flash cm13 (a custom rom). On cm13 I've realised it works only on temperatures more than 65-70*.
I suggest you to keep your opt cool as long as you can.

Mine started flickering just after I made a change in Settings, and it was Turning OFF Adaptive Brightness

Mine just started flickering after I didn't change anything at all. Never used adaptive brightness in my life.

Always On Display bug/issue after latest Firmware update 09.April.16?

Hey, i updated to the latest firmware that came out today 9. april 2016. Firmware version : G935FXXU1APD1/G935FNEE1APC5/G935FXXU1APD1. My Phone is a Nordic Edition S7E with Carrier Telenor Norway.
after the update everything works like it should except the Always on Display. The AoD works but its always on the lowest brightness... it moves around, shows what i ask etc but it wont get brighter when i go outside or shine something at it, auto brightness works fine on the screen when its on. my question is: does this happen to anyone else? this has to be a software bug within the AoS app or the OS itself :/ cheers

What version does it show in the AOD settings ( About AOD)

Version 1.1.14

I guess its a change, this is the version i have. Im on fw PB6

it seems like it does work tho much slower than before, i think they tweaked the sensitivity on the brightness, because before it changed waaaaaay to easy, now it stays on the right brightness for the area you are in, tho if you go from a dark room to a bright room it takes waaaaaaaaay to long for it to change, and when you take it out of you're pocket it will still be on the lowest brightness for some reason... so AoD is now useless outdoors if its sunny out, ill guess they will change it again since i think they over did it.

it is not a problem it is intended to reduce power uage.

antenehnile said:
it is not a problem it is intended to reduce power uage.
Click to expand...
Click to collapse
iknow that, but the point of AoD is that you should not need to turn ON your display, now you have to if you are outside, since the update rate it so low on the brightness. for indoor use its awesome tho.

Zychic said:
iknow that, but the point of AoD is that you should not need to turn ON your display, now you have to if you are outside, since the update rate it so low on the brightness. for indoor use its awesome tho.
Click to expand...
Click to collapse
Idk about the brightness, mine bases itself off of lighting around me. As for it moving, that is to save your screen from AMOLED burn in.
I have a real problem with AOD, after the latest T-Mobile April security update, AOD doesn't move and it should to prevent burn in. I currently have it turned off until it's fixed.
My AOD version 1.1.17
Sent Via My Samsung S7 Edge

Rydah805 said:
Idk about the brightness, mine bases itself off of lighting around me. As for it moving, that is to save your screen from AMOLED burn in.
I have a real problem with AOD, after the latest T-Mobile April security update, AOD doesn't move and it should to prevent burn in. I currently have it turned off until it's fixed.
My AOD version 1.1.17
Sent Via My Samsung S7 Edge
Click to expand...
Click to collapse
i know it has to move the issue is that it takes so long for the brightness to increase/decrease after the update when the light changes in the room/place you are, so when you are outside and take your phone out its on the lowest brightness, so you cant see anything, it takes over 20 sec before it increases the brightness. but why there is so many " latest version" of the AoD is weird if you ask me. it worked before the firmware update tho it increased the brightness to the max much easier before, so it used a lot of battery, i think they tried to fix this but overdid it. that is why i'm asking if its happening to anyone else.

Zychic said:
i know it has to move the issue is that it takes so long for the brightness to increase/decrease after the update when the light changes in the room/place you are, so when you are outside and take your phone out its on the lowest brightness, so you cant see anything, it takes over 20 sec before it increases the brightness. but why there is so many " latest version" of the AoD is weird if you ask me. it worked before the firmware update tho it increased the brightness to the max much easier before, so it used a lot of battery, i think they tried to fix this but overdid it. that is why i'm asking if its happening to anyone else.
Click to expand...
Click to collapse
Oh, sorry I misread that. I thought you were having multiple issues. Yes, mine takes forever too.
I don't know why they just don't put it in the Galaxy App Store so that all can have the latest version.
Sent Via My Samsung S7 Edge

Rydah805 said:
Oh, sorry I misread that. I thought you were having multiple issues. Yes, mine takes forever too.
I don't know why they just don't put it in the Galaxy App Store so that all can have the latest version.
Sent Via My Samsung S7 Edge
Click to expand...
Click to collapse
Yeah they really should put it in the app store, just like they did with the edge features, but i didnt receive the new updates yet, so im waiting for it

i did a test now, it only changes brightness when the AoD moves for me, i guess that is how it should work, i don't remember how often i did back on the PB4 firmware but it was much more sensitive that is for sure.

latest firmware did break AOD for me too, T-Mobile US. AOD no longer moves. Not sure if I noticed before but waking the screen up now with power or home button, the screen fades in somewhat. It's a very quick fade in but noticeable because it's not instant.

I am seeing some serious problems with the AOD- I even asked for an exchange thinking something was defective. I got my new phone today and it reacts in the exact same way: AOD brightness changes completely at random ie I am not able to see any sort of correlation between how dark/light it is where I am. AOD version is 1.1.06, while the firmware version is PB9.
The other issue I am seeing is with GPS- worst that I have seen until now. I tried it with GMaps and a couple similar apps- the arrow that shows the direction does not move around based on which way the phone is pointing. This was the exact same on the phone that I sent back in exchange for the new one this morning..

NYanakiev1 said:
I am seeing some serious problems with the AOD- I even asked for an exchange thinking something was defective. I got my new phone today and it reacts in the exact same way: AOD brightness changes completely at random ie I am not able to see any sort of correlation between how dark/light it is where I am. AOD version is 1.1.06, while the firmware version is PB9.
The other issue I am seeing is with GPS- worst that I have seen until now. I tried it with GMaps and a couple similar apps- the arrow that shows the direction does not move around based on which way the phone is pointing. This was the exact same on the phone that I sent back in exchange for the new one this morning..
Click to expand...
Click to collapse
How do You change Your phone ? What arguments You have for a phone change ? I just wonder how people exchange their phones so easily.

Monkey Slut said:
How do You change Your phone ? What arguments You have for a phone change ? I just wonder how people exchange their phones so easily.
Click to expand...
Click to collapse
Well, I got the phone on my new contract less than 30 days ago ie I am entitled to an exchange as opposed to having to send the phone in for repairs.

Has the latest update enabled displaying all notifications, not only calls and sms messages ? If not, better turn it off and be done with it. It's useless.

Cst79 said:
Has the latest update enabled displaying all notifications, not only calls and sms messages ? If not, better turn it off and be done with it. It's useless.
Click to expand...
Click to collapse
Nah its still as useless. I disabled, it jjst drains battery

Mine is now showing a grey background. Anyone has this issue? I can't get it to go back to black.

bsm123 said:
Mine is now showing a grey background. Anyone has this issue? I can't get it to go back to black.
Click to expand...
Click to collapse
Help? Anyone?

[TIP] Reduce screen burn in on your LG G5

I had problem of "screen burn in" on my LG G5 and I tried different apps which reduce the burn in for time being but they didn't solve the issue.
Recently I tried "turning off the always on display" and I have noticed that the screen burn in is reduced by 80% I can barely see the burn in previously I was able to clearly see the burn in.
Also don't let your phone get too hot like really hot, burn in is maximum when the phone is very hot.
Hope these tips help you.
P.S. Please try these tips and post replies if they worked for you.

Wish it would help bit doesnt... Since day 1 always on is turned off and the phone doesnt get too warm... It`s the brightness or whatever that causes this

My friend just change theme and after that dont have burn in effect. You can try

I think the burn effect is caused by blue subpixels, so you need to lower the brightness of these. I'm using the built in color control in cyanogenmod but you can use an app like CFlumen or Twilight, Blue Light Filter, etc. I had no more status bar icons stuck.

Yes it mostly happens to me in summer/high degrees also when the phone over heats
Sent from my VS987 using Tapatalk

sayyro said:
Yes it mostly happens to me in summer/high degrees also when the phone over heats
Sent from my VS987 using Tapatalk
Click to expand...
Click to collapse
i have noticed retention not burn in but a lot less noticable at dark themes such as mine is set to the basic black high contrast.
my rention happend almost over night i can see the help icon on the screen from the home screen.
which is weird cause that icon has ever rarely been displayed

TheMadScientist420 said:
i have noticed retention not burn in but a lot less noticable at dark themes such as mine is set to the basic black high contrast.
my rention happend almost over night i can see the help icon on the screen from the home screen.
which is weird cause that icon has ever rarely been displayed
Click to expand...
Click to collapse
That's why I'm using the black themed Gboard on my G5
Sent from my VS987 using Tapatalk

sayyro said:
That's why I'm using the black themed Gboard on my G5
Sent from my VS987 using Tapatalk
Click to expand...
Click to collapse
I most def wont call it burn cause burn stays on almost all the screens this is never on white black. Just at random times. More like when screen animations are happening

I just use Blue Light Filter (Dev is hardy infinity). I've been using it for the past 7 months or so ..solved all my issues with the screen . If I turn it off, I have very bad images retention. Works perfect. Install and forget it's there.

galr said:
I just use Blue Light Filter (Dev is hardy infinity). I've been using it for the past 7 months or so ..solved all my issues with the screen . If I turn it off, I have very bad images retention. Works perfect. Install and forget it's there.
Click to expand...
Click to collapse
I'll try it, thanks.

If you are rooted you can set bgr by installing some kernel. If you are using custom rom, you can just set colors in color calibration to 90% (all three). For people with no root, use blue light filter and thats it..

ebisa said:
I'll try it, thanks.
Click to expand...
Click to collapse
Set it to 6 or 7 percent.

galr said:
I just use Blue Light Filter (Dev is hardy infinity). I've been using it for the past 7 months or so ..solved all my issues with the screen . If I turn it off, I have very bad images retention. Works perfect. Install and forget it's there.
Click to expand...
Click to collapse
Hello. What about nav bar? I have been using an app called sFilter bluelight app and it clearly removes image retention except the navigation bar, that one you say can help me with this?

Pistacho123Lol said:
Hello. What about nav bar? I have been using an app called sFilter bluelight app and it clearly removes image retention except the navigation bar, that one you say can help me with this?
Click to expand...
Click to collapse
Unfortunately can't touch the NAV bar. Change it to Black color to have less effect.

galr said:
Unfortunately can't touch the NAV bar. Change it to Black color to have less effect.
Click to expand...
Click to collapse
Ohh, allright. Thanks for the tip

Pistacho123Lol said:
Ohh, allright. Thanks for the tip
Click to expand...
Click to collapse
Use Night screen (Paper airplane dev team).
change to system overlay mode.
It'll cover the whole screen including the navbar

ChristopherXI said:
Use Night screen (Paper airplane dev team).
change to system overlay mode.
It'll cover the whole screen including the navbar
Click to expand...
Click to collapse
Ok, so i have just downloaded the app and changed to that mode, anything else to do? Change brightness, etc.?

Pistacho123Lol said:
Ok, so i have just downloaded the app and changed to that mode, anything else to do? Change brightness, etc.?
Click to expand...
Click to collapse
my screen got a really bad case of image retention so i set the slider at about 80% (far to the right).
even with maximum brightness i don't get image retention anymore.
If you reboot the phone it wont automatically start by itself. you have to manually turn it on again.

ChristopherXI said:
my screen got a really bad case of image retention so i set the slider at about 80% (far to the right).
even with maximum brightness i don't get image retention anymore.
If you reboot the phone it wont automatically start by itself. you have to manually turn it on again.
Click to expand...
Click to collapse
Allright:good:. Thank you very much!

ChristopherXI said:
Use Night screen (Paper airplane dev team).
change to system overlay mode.
It'll cover the whole screen including the navbar
Click to expand...
Click to collapse
This is the best recommendation I have read on this issue for a long time. This app works like a charme. Perfect for everyone struggling with image retention on his lg g5. And you even don't have to change the colors. It just lays a mask over your display and that's it. :good:

[Obsolete] Yoga Tab 3 Plus no more Flickering/CABC [ROOT]

Update
Lenovo fixed the issue in the latest update with my initial method which was switching off the CABC in the backlight controller which gives us a brightness boost. So obviously it is not dangerous.
Old Message:
So having achieved root, I was looking into the easiest of the issues. Some call it flickering. The "feature" is called CABC and is supposed to save battery. But obviously this comes at a cost of the display constantly adapting the brightness to the content which can cause flickering depending on what you have on the screen.
With root this can be switched off. Alternatively a new kernel could solve this without root. In both cases an unlocked bootloader is still required.
Instructions:
Use a build.prop editor form the Playstore
Edit the variable "ro.qualcomm.cabl=2" and set it to 0. CAUTION this modifies the system partition. If you want to receive OTAs in the future you will have to flash the system partition with an original image or backup.
Reboot
Technical details:
There are three places where CABC can be switched off:
In the build.prop
In the device tree blob in the boot image/kernel. Specifically the DSI switch on commands in the LCD panel description contain the enabling of CABC
In the LCD backlight driver /sys/devices/soc.0/78b6000.i2c/i2c-2/2-002c -> could be dangerous because it increases brightness and the voltages in the backlight controller

matshias said:
So having achieved root, I was looking into the easiest of the issues. Some call it flickering. The "feature" is called CABC and is supposed to save battery. But obviously this comes at a cost of the display constantly adapting the brightness to the content which can cause flickering depending on what you have on the screen.
With root this can be switched off. Alternatively a new kernel could solve this without root. In both cases an unlocked bootloader is still required.
I attached an Automate flow which disables CABC and guess what we get a brightness bump of about 20%. Now the maximum brightness of the display is even a bit brighter than my old Yoga Tab 2 and should be on par with the 3 pro
Make sure that Automate runs on system startup and has root enabled.
Technical details:
There are two places where CABC can be switched off:
In the device tree blob in the boot image/kernel. Specifically the DSI switch on commands in the LCD panel description contain the enabling of CABC
In the LCD backlight driver /sys/devices/soc.0/78b6000.i2c/i2c-2/2-002c
It turns out that if you disable the latter CABC is off even without modifying the former. Of course this requires ROOT to change. This could also be done in the kernel, but would need either a recompile or modifying the init.rd
Click to expand...
Click to collapse
Thanks Now only audio sync issues left for me and tablet will be perfect.

Have you compared the battery performance with and without CABC disabled?

Ashili said:
Have you compared the battery performance with and without CABC disabled?
Click to expand...
Click to collapse
No, these battery life tests take a long time, which I don't have Time is better spent looking into the other issues. It shouldn't be too much of a difference.

matshias said:
No, these battery life tests take a long time, which I don't have Time is better spent looking into the other issues. It shouldn't be too much of a difference.
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Yap, I think so. The battery life is long enough. Thank you.

I would think as long as you manually adjust brightness to match your content, you'd get similar results.

I modified the thread to use a less invasive method. I am having issues with my tablet. I am not sure it was caused by this mod but just to be safe I recommend everyone not to use it any longer.

what kind of problem?

chuwq1038 said:
what kind of problem?
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Everything works (also the display) but the battery drains and the back of the tablet gets warm even when the tablet is switched off. Could be completely unrelated to the mod, but who knows.

With latest official update I have a battery drain issue too. 15% down overnight...