Develop Bugs

[Tips] Screen Color Calibration for the Galaxy Nexus

After using the Galaxy Nexus for two weeks, I found the screen color of the new amoled+ is much better than the Nexus S, but still inaccuracy. I'm a part-time photographer who keen on the right Gamma, color accuracy and color temperature.
So I just finished some test with such things:
Galaxy Nexus
franco Kernel 18.5 nightly(with the ColorControl from Ezekeel)
Voodoo Screen Test app
x-rite i1 Display 2 color meter
HCFR software
The test result was not so good...
Average Gammar value is about 1.9, far from the ISO stand 2.2. So the color is just too bright (I'm not saying screen brightness).
The shadow part (0-40% gray level) of 3 color curve were almost out of trim. In another words, incaauracy color balance.
As the color unbalance. The color temperature is starting from lower than 5500K to 6500K, which the ISO stand is 6500K at any color level.
I also tested the ColorControl in franco Kernel. After the adjustments, Gammar value is still bad, but I save the (most part of) color balance & color temperature in the end.
The adjustments step by step:
Make sure you have a rom/mod with /init.d autorun function.
Bye, stock rom...
Make sure you have a kernel with ColorControl function.
Such like Ezekeel, franco...Else? I don't know.
Set the screen brightness to 50%.
It's the mesurement "baseline". But why 50%?
Because, at this point the screen has a brightness about 120 Lux--also a ISO stand. So, it's very close to our desktop LCD.
Make a new file as /etc/init.d/900colorcontrol-b50
Which could be done by Root Explorer or adb.
Inside the file, type such line:
Code:
echo "-10 0 -10" > /sys/class/misc/colorcontrol/v1_offset
echo "1820000000 1900000000 2000000000" > /sys/class/misc/colorcontrol/multiplier
I choose "182 190 200" here, because the default value was about 200. Rising will increase the risk of LED Burn-in.
And, don't forget the 7 zero!!!
Just reboot & enjoy the almost right color temperature.
It's (6500±300)K at any color level in my device. Not perfect, but much better indeed.
Done, that's all I can do for you.

Thanks so much for the mod.
I'm willing to test your new calibration for the GNex color but how can I revert back to stock in case of problem ?
So I guess we can only use this modification at 50% of brightness ? If we change to auto, how could it be ?

Sorry for being a noob here, but this is compatible with any rom/kernel right? I'm currently running on AOKP Build 25 and Popcorn kernel 7.1
Thanks,
Mosh

Hi, and thank you for offering your expertise. I'm not confident in doing the above.... Can you offer a little bit more step by step?
I've played around with root explorer which I imagine is what is necessary to change these values.you lost me at the 2nd step.....
Also, is 50% necessary?
Thanks kindly,
_______________________________
frAncO Kernel ;-P

mazubo said:
Hi, and thank you for offering your expertise. I'm not confident in doing the above.... Can you offer a little bit more step by step?
I've played around with root explorer which I imagine is what is necessary to change these values.you lost me at the 2nd step.....
Also, is 50% necessary?
Thanks kindly,
_______________________________
frAncO Kernel ;-P
Click to expand...
Click to collapse
mohitrocks said:
Sorry for being a noob here, but this is compatible with any rom/kernel right? I'm currently running on AOKP Build 25 and Popcorn kernel 7.1
Thanks,
Mosh
Click to expand...
Click to collapse
heo_con184 said:
Thanks so much for the mod.
I'm willing to test your new calibration for the GNex color but how can I revert back to stock in case of problem ?
So I guess we can only use this modification at 50% of brightness ? If we change to auto, how could it be ?
Click to expand...
Click to collapse
Step by step detail added. Thx for reading~

Thanks for the guide!
Sent from my Galaxy Nexus using XDA App

You can change all of these settings from Franco's kernel updater program directly without modifying any files.
The OP's settings appear a little warm at first but I'm liking them so far...
Sent from my Galaxy Nexus using xda premium

Can you please add this file 900colorcontrol-b50

sooooo do i make a folder in system like this?
system/etc/init.d/900colorcontrol-b50 and then add that text above or??

Instead of making that script, can we just input those numbers into the Color Control?
-10, 0, -10 for Gamma (RGB);
182, 190, 200 for Multiplier (RGB)
Right?

Thank!
your feeling about color is exactly. Gray is dirty, it's not sync at all pixels.
I hope someone changes this by kernel - easy for me control everything
After flash franco kernel it's better more but not perfect.
If this problem is not improved, i'll buy other phone that uses Superamoled PLUS replace this one . HIZzzz

These settings look green to me
Sent from my Galaxy Nexus using Tapatalk

Indeed... especially settings menu looks very greenish!
But maybe I get used to it...
Edit: Maybe a typo? '-10 0 10' looks not that bad at all ;-)
jornbjorn said:
These settings look green to me
Sent from my Galaxy Nexus using Tapatalk
Click to expand...
Click to collapse

phunghoang24 said:
Thank!
your feeling about color is exactly. Gray is dirty, it's not sync at all pixels.
I hope someone changes this by kernel - easy for me control everything
After flash franco kernel it's better more but not perfect.
If this problem is not improved, i'll buy other phone that uses Superamoled PLUS replace this one . HIZzzz
Click to expand...
Click to collapse
And that would do absolutely nothing
SAMOLED Plus displays are identical to the SAMOLED HD displays when it comes to colors and such.

It would be better and more easy if someone was able to do an app like this one that works for the Nexus One :
http://forum.xda-developers.com/showthread.php?t=745248
I really miss this app since I've bought my Galaxy Nexus

Thanks for the info. I had mine looking very similar but with a combination of lower brightness and higher multiplier values. Nice to have it set now without the additional risk of burn in. Thanks a ton.

screen looks greenish compared to franco's recommended value, using his instead but thanks for the write up.

kashix said:
screen looks greenish compared to franco's recommended value, using his instead but thanks for the write up.
Click to expand...
Click to collapse
must be a typo in his gamma settings -10,0,10 is ALOT better (=

Great find colors are much more accurate now

These settings are way off on my device, its too green.

[SOURCE | MINNOW] Kitkat Kernel Source for Moto 360

Hey folks,
as everyone knows, due to the GPL every company who creates android images is forced to release the kernel source!
I started digging around in the internet and found the sources at Googles git server.
The kernel is based on top of linux kernel version 3.10.x, so here we go:
https://android.googlesource.com/kernel/omap/+/android-omap-minnow-3.10-kitkat-wear
After i found and ordered a nice usb connector for my Moto 360 which i got last thursday,
i will start creating custom kernels and port over a modded version of cm
(which may takes a while as i have to create a few interface layouts first! ofcourse whishes and ideas are welcome).
Best regards,
OldDroid

Good luck man!

Oh fun. Huh turns out they lowered the standard fps to 45, and in ambient mode its capped down to 30. For battery I guess.
Thanks OMAPa!

Metallice said:
Oh fun. Huh turns out they lowered the standard fps to 45, and in ambient mode its capped down to 30. For battery I guess.
Thanks OMAPa!
Click to expand...
Click to collapse
Hm, why would you need 30fps in the dimmed mode (No seconds had there anyway)?
Or are we talking about the normal screen on state with ambient enabled?
Would lowering this further enhance the battery effiency significantly?

Diamondback said:
Hm, why would you need 30fps in the dimmed mode (No seconds had there anyway)?
Or are we talking about the normal screen on state with ambient enabled?
Would lowering this further enhance the battery effiency significantly?
Click to expand...
Click to collapse
I think he means the normal screen rate is 30fps with ambient enabled...
I wouldn't mind upping the rate to 60fps because the watch last me a full day with plenty battery left over ... This way we can at least have a smoother experience
Sent from my HTC One using Tapatalk

thesparky007 said:
I think he means the normal screen rate is 30fps with ambient enabled...
I wouldn't mind upping the rate to 60fps because the watch last me a full day with plenty battery left over ... This way we can at least have a smoother experience
Sent from my HTC One using Tapatalk
Click to expand...
Click to collapse
Yep the panel can definitely do 60fps. According to the source that was what it was originally set to. Wouldn't be too tricky to revert the relevant changes.
Edit: there actually is a time when the panel runs at 60fps... On the charger :/

Metallice said:
Yep the panel can definitely do 60fps. According to the source that was what it was originally set to. Wouldn't be too tricky to revert the relevant changes.
Edit: there actually is a time when the panel runs at 60fps... On the charger :/
Click to expand...
Click to collapse
Haha, yea that totally makes sense :victory: Did you spot yet which cpu governor we are running on by default?

Userspace. Its probably set in the ramdisk on boot like all the other nexuses. Based on older commits it is probably interactive but you'd have to look at the init files to be sure.

There are a lot of interesting things to tweak here not just frame rate. Gestures and sensitivity, frequencies/scaling/voltages, screen/misc timeouts, lots and lots of stuff can be tweaked with ambient mode - the timeouts, the max brightness for the ULP display state, and so on. Looks like we could even go revert back to "normal" ambient mode for those that want it.

there can be made various battery related changes
maybe i gonna try to implement blx (battery life extender) at the weekend, but we will see
i think some governor tweaks can be done aswell ... (don't know if touch boost interface has been implemented by motorola, will check later)

OldDroid said:
there can be made various battery related changes
maybe i gonna try to implement blx (battery life extender) at the weekend, but we will see
i think some governor tweaks can be done aswell ... (don't know if touch boost interface has been implemented by motorola, will check later)
Click to expand...
Click to collapse
If you are referring to caf CPU boost then no it is not in this kernel.

MikeC84 said:
If you are referring to caf CPU boost then no it is not in this kernel.
Click to expand...
Click to collapse
thx for looking it up!

Diamondback said:
Haha, yea that totally makes sense :victory: Did you spot yet which cpu governor we are running on by default?
Click to expand...
Click to collapse
yep, it's interactive:
Code:
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
it's set in init.minnow.rc

Sweet thanks for the link. As for features, can't think of much that isn't already handled via setting proc settings (screen off on charge etc), perhaps add an App that can make these configurable via a GUI?
This probably needs messing around with /system, but my biggest annoyance is probably the fact that cards always cover up my analog faces unless I mute, which still adds the mute logo so not the best solution.

What USB connector did you order?
Sent from my HTC One_M8 using XDA Free mobile app

blacklistedcard said:
What USB connector did you order?
Sent from my HTC One_M8 using XDA Free mobile app
Click to expand...
Click to collapse
I am curious, too, as I do not want to make my own, but want to BL unlock and root.

r3pwn said:
I am curious, too, as I do not want to make my own, but want to BL unlock and root.
Click to expand...
Click to collapse
Me too.. Coz I want to participate with this project without messing with home made cables. Mind to share it?
Sent from my XT1033 using XDA Free mobile app

I want to build a custom kernel for this guy. There are a lot of cool things I could do with CPU scaling, voltages, and ambient mode settings.
Unfortunately I reeeaally don't want to try to hack together my own cable. Hopefully someone will sell one but it seems unlikely.

Metallice said:
I want to build a custom kernel for this guy. There are a lot of cool things I could do with CPU scaling, voltages, and ambient mode settings.
Unfortunately I reeeaally don't want to try to hack together my own cable. Hopefully someone will sell one but it seems unlikely.
Click to expand...
Click to collapse
Yeah, newer toolchain and some optimizations would really help that old processing in the Moto 360. I just wish we did not have you use a custom cable.

Will it ever be possible root over adb? Or through the NFC charger plugged into a PC?
Sent from my XT1097 using XDA Free mobile app

Guide to get more vivid colors & better looking screen

Ever since i got rid of my pixel for this i had issues getting used to the screen colors looking so blah and dull but here's na way to fix it for you...flash a kernel that supports kcal (like alize) and with kernel auditor or a kernel manager app go to screen and increase "Saturation intensity" to about 45 and "Minimal RGB value" to about 50.....it looks some much better and sacrifices nothing...i just thought id share...hope you enjoy it as much as I am...

Thanks for this. The only thing of this phone that I don't like it's the screen colors.
Wish I could fix this without root. But it'll use it in the future if I root sometimes.
Thanks again

Fix quick settings and notification bar stutter and lag

Pull down quick settings, press 'edit', tap the 3 dot menu and uncheck all the boxes.
Just discovered this today. The lag used to be unbearable and was thinking about replacing the phone with a Nexus 6p or HTC 10.
Then I discovered this and the shade is completely buttery now, and plus, looks more like stock android!!
Hope this helps other people as it did to me.

MDW 100 said:
Pull down quick settings, press 'edit', tap the 3 dot menu and uncheck all the boxes.
Just discovered this today. The lag used to be unbearable and was thinking about replacing the phone with a Nexus 6p or HTC 10.
Then I discovered this and the shade is completely buttery now, and plus, looks more like stock android!!
Hope this helps other people as it did to me.
EDIT: I swear the fingerprint scanner is faster now and the whole UI is even smoother... Wow.
Click to expand...
Click to collapse
You're talking about that ? (see screenshot)
I think it's a placebo effect, I do not see why some shortcuts would slow down the phone completely..
In addition the tab for brightness is very convenient to reset the automatic brightness when the phone takes time to change or remains blocked on a dim light (it's a problem on this phone I think, it's not very effective on auto brightness)
In any case I tried to see, for my part I do not see any difference, the phone has exactly the same behavior as the shortcuts is on !

I forgot the screenshot :angel:

Maybe it's different for other people. When I had those enabled, it definitely was jerky to pull down quick settings, especially using the swipe down shortcut on my launcher. Now it's really smooth for me, which is how it should be with a sd 821. Shouldn't be a challenge for it.
I did find the brightness slider useful but, and I know this sounds weird, I would happily trade those shortcuts (including 'file sharing' etc. which I never used) for a much smoother and cleaner looking notification shade (and btw I have next to 0 lag tolerance... Should have got a Pixel ?). Instead I used Nougat/Oreo Quick Settings to change it to a quick settings toggle and I think this is a good solution considering that personally I hardly ever change the brightness from auto.
Thanks for the reply, interesting how some G6s seem to lag and others don't. Also I've never had a problem with auto brightness ?

MDW 100 said:
Maybe it's different for other people. When I had those enabled, it definitely was jerky to pull down quick settings, especially using the swipe down shortcut on my launcher. Now it's really smooth for me, which is how it should be with a sd 821. Shouldn't be a challenge for it.
I did find the brightness slider useful but, and I know this sounds weird, I would happily trade those shortcuts (including 'file sharing' etc. which I never used) for a much smoother and cleaner looking notification shade (and btw I have next to 0 lag tolerance... Should have got a Pixel ?). Instead I used Nougat/Oreo Quick Settings to change it to a quick settings toggle and I think this is a good solution considering that personally I hardly ever change the brightness from auto.
Thanks for the reply, interesting how some G6s seem to lag and others don't. Also I've never had a problem with auto brightness ?
Click to expand...
Click to collapse
Interestingly enough, I've done the same as you.
The problem in doing this is how difficult it is to find this toggle when your brightness is EXTREMELY low and the sun is beaming in your face. Unlike having a whole row to tap on and adjust, you have to tap on one singular point on your display, and I found this frustrating.
Anyways, disabling everything in that list did help with the lag a bit. Even if it was just barely noticeable.

The improvement was more than barely noticeable for me... Made it seem like a software bug.
Having said that, I don't think it's acceptable for a company like LG to release a phone at this price that has any lag issues at all, agree? I'll have spent $674 equiv. just on the phone by the time my contract is up. Loved the phone overall, thought the lag might improve, also thought I would promptly get Oreo (being LG) which might help. None of those happened, and I ran out of time to return it. Silly me...

MDW 100 said:
Maybe it's different for other people. When I had those enabled, it definitely was jerky to pull down quick settings, especially using the swipe down shortcut on my launcher. Now it's really smooth for me, which is how it should be with a sd 821. Shouldn't be a challenge for it.
I did find the brightness slider useful but, and I know this sounds weird, I would happily trade those shortcuts (including 'file sharing' etc. which I never used) for a much smoother and cleaner looking notification shade (and btw I have next to 0 lag tolerance... Should have got a Pixel ?). Instead I used Nougat/Oreo Quick Settings to change it to a quick settings toggle and I think this is a good solution considering that personally I hardly ever change the brightness from auto.
Thanks for the reply, interesting how some G6s seem to lag and others don't. Also I've never had a problem with auto brightness ?
Click to expand...
Click to collapse
Maybe it depends on the version of the phone, I'm on h870
On mine auto brightness is really slow, sometimes I need to adjust myself because it is sometimes too strong or too weak compared to the situation, maybe my sensor that is badly calibrated..
Otherwise I agree, sharing files is useless and for the volume I already have the keys, so it is disabled on my side.
It is true that we see a lot of different returns depending on the users of this phone, especially on performance and autonomy, personally I'm lucky, good performance, good battery life and good focal length (2.01)

coyot352 said:
Maybe it depends on the version of the phone, I'm on h870
On mine auto brightness is really slow, sometimes I need to adjust myself because it is sometimes too strong or too weak compared to the situation, maybe my sensor that is badly calibrated..
Otherwise I agree, sharing files is useless and for the volume I already have the keys, so it is disabled on my side.
It is true that we see a lot of different returns depending on the users of this phone, especially on performance and autonomy, personally I'm lucky, good performance, good battery life and good focal length (2.01)
Click to expand...
Click to collapse
Yeah auto brightness is pretty slow to react on mine too...
I also have a European H870. It has moments of absolute fluidity out of the blue and it's awesome, and also moments of being so bogged down it's unusable. Everything else is somewhere in between. It feels like a fast phone but it doesn't feel like a OnePlus 3t, which has the same chipset. That's even after debloating the phone almost entirely. I don't really want to install a custom ROM like LOS yet, although I've heard that helps.

If your LG G6 is rooted, install a custom kernel, from Play Store try L Speed/Entropy/fstrim apps should help, if you installed a custom kernel, play using Kernel Adiutor. Settings/Developer Options/ tick on "Force GPU Rendering, Disable HW Overlays" should make the beast smoother/snappier. Install adblocker too.
This is the better solution for stuttering/lag.

Ali Mirza said:
If your LG G6 is rooted, install a custom kernel, from Play Store try L Speed/Entropy/fstrim apps should help, if you installed a custom kernel, play using Kernel Adiutor. Settings/Developer Options/ tick on "Force GPU Rendering, Disable HW Overlays" should make the beast smoother/snappier. Install adblocker too.
This is the better solution for stuttering/lag.
Click to expand...
Click to collapse
I do not have root at the moment on my phone, but when I do, I will give Kernel Adiutor a try. Thanks!

h870 here, unchecking these boxes didnt make any difference.
although i have to agree that this phone is sometimes weirdly laggy while usuall being smooth most of the time

Thx for letting us know about that menu! Those settings don't produce stuttering for me thankfully, but I disabled them anyway and enabled the volume slider which I love to have there
nice!
The only thing that creates slight stutters (very rare though) on my Orea LG G6 is when I use the ported pixel 2 live wallpapers.

Kernel mods - are display gamma correction and refresh rate overclocking possible?

Got a V30 a few months ago - brilliant device but not that happy with the display - it has the very annoying "black crush" issue for me.
Short explanation (it's better you don't read - trust me it can be very annoying when you're aware of it):
The lower the screen brightness is set, dark grays and dark colours are shown completely black when they shouldn't - this is very annoying as the detail in darker areas of images completely disappears (it's bad for all content - pictures, videos, games). It can vary from device to device, even on the same models.
This is an issue at varying degrees on other OLEDs too such as Pixels', Samsung, OnePlus; but Apple and Huawei seem keep it mostly under control. Funny enough my old Galaxy S4 does not really have this issue.
Google and Samsung managed to partially fix it (completely for some users) with software updates, so this should be possible for us too especially as V30 has the exact same display as Pixel 2 XL which got some improvement via update if I remember correctly.
There are apps and tricks which claim to improve this but while they can help a bit they bring in other issues.
Looking for fixes I found this V30 kernel - "Savitar-OC-kernell" - a claimed feature was refresh rate OC (80Hz). The thread is closed, the links are dead, the dev didn't respond (PM'd months ago) and there is no video proof of it so I can't really be sure that it worked well or at all. But if true then it means there is at least a way to get very low level control of the display panel.
I have zero experience with kernel/ROM development but I can get technical so I did some (probably bad) research myself. Downloaded the kernel source from LG.
Found some interesting files here:
...\kernel\msm-4.4\drivers\video\fbdev\msm\lge\joan\
...\kernel\msm-4.4\arch\arm64\boot\dts\lge\
My guess is that V30's panel is "sw43402" (I think that's the driver IC model, same as 2 XL) - there are multiple files for it, with values for front/back porch, clk etc. which is what I suspect was modified for the refresh overclock.
Also found multiple entries/tables? for "gamma" and "blmap" (backlight map?) values which is what I hope can be used for a fix for the black crush.
My hope is that there is a way to tweak the gamma curves or some other form of display mapping. At 100% brightness my phone display is almost perfect, zero black crush. However as I set the brightness lower the black crush amount varies (it's not linear or exponential, it's "jumpy") which looks like there is some sort of mapping trying to compensate.
I'd love to hear your opinion especially if you have any experience with this stuff or if you can forward this to someone you know could answer. I would appreciate if you can tell whether you think this is possible and whether what I found is on the right track. Thanks for reading all this.

gamma correction
Click to expand...
Click to collapse
your best bet is via KCAL or KLAPSE in custom kernels
recommendation-based is to not go lower than 30 or 50% in brightness otherwise you'll lose details
refresh rate overclocking
Click to expand...
Click to collapse
not worth it, there's no true close hardware manipulation possible (like with Exynos kernel source) also OLED panels are sensitive (high brightness, burn-in, etc.) and (relatively?) short-lived already - why shortening life even more ?

Thanks for the reply.
KCAL seems to be a step in the right direction however I don't think I can find any kernel for V30 that has it. I'll look into KLAPSE but it seems that it won't help "out of the box" without some lower level modifications.
Refresh rate - sure it may not be very practical but I don't think it's that dangerous (One example being the overclocked Note 3 displays in the Oculus DK2 back in 2014). 80Hz may be too much (and may be ghosting) but even 67-72 should make a noticeable difference. And why not have it as an option - for science - or for people that plan to upgrade soon and want to go crazy with it.
zacharias.maladroit said:
there's no true close hardware manipulation possible
Click to expand...
Click to collapse
Can you please expand on this? What about the files I mentioned? An example snippet from
dsi-panel-sw43402-dsc-qhd-cmd-dv2_0.dtsi
Code:
[FONT="Courier New"]...
&mdss_mdp {
dsi_sw43402_dsc_qhd_cmd_dv2_0: qcom,mdss_dsi_sw43402_dsc_qhd_cmd_dv2_0 {
qcom,mdss-dsi-panel-name = "SW43402 cmd mode dsc dsi panel";
qcom,mdss-dsi-panel-type = "dsi_cmd_mode";
qcom,mdss-dsi-panel-framerate = <60>;
qcom,mdss-dsi-virtual-channel-id = <0>;
qcom,mdss-dsi-stream = <0>;
qcom,mdss-dsi-panel-width = <1440>;
qcom,mdss-dsi-panel-height = <2880>;
qcom,mdss-dsi-h-front-porch = <92>;
qcom,mdss-dsi-h-back-porch = <48>;
qcom,mdss-dsi-h-pulse-width = <32>;
qcom,mdss-dsi-h-sync-skew = <0>;
qcom,mdss-dsi-v-back-porch = <25>;
qcom,mdss-dsi-v-front-porch = <10>;
qcom,mdss-dsi-v-pulse-width = <1>;
...[/FONT]
I'd imagine something should happen if these are modified, or do you think nothing would happen? Some gamma and blmap tables are also further down in the file.
However there are multiple similar files in that folder which is a bit confusing to me. Any clue if there's public documentation on this or at least what to search for to understand it further?

cLick1338 said:
Got a V30 a few months ago - brilliant device but not that happy with the display - it has the very annoying "black crush" issue for me.
Short explanation (it's better you don't read - trust me it can be very annoying when you're aware of it):
The lower the screen brightness is set, dark grays and dark colours are shown completely black when they shouldn't - this is very annoying as the detail in darker areas of images completely disappears (it's bad for all content - pictures, videos, games). It can vary from device to device, even on the same models.
This is an issue at varying degrees on other OLEDs too such as Pixels', Samsung, OnePlus; but Apple and Huawei seem keep it mostly under control. Funny enough my old Galaxy S4 does not really have this issue.
Google and Samsung managed to partially fix it (completely for some users) with software updates, so this should be possible for us too especially as V30 has the exact same display as Pixel 2 XL which got some improvement via update if I remember correctly.
There are apps and tricks which claim to improve this but while they can help a bit they bring in other issues.
Looking for fixes I found this V30 kernel - "Savitar-OC-kernell" - a claimed feature was refresh rate OC (80Hz). The thread is closed, the links are dead, the dev didn't respond (PM'd months ago) and there is no video proof of it so I can't really be sure that it worked well or at all. But if true then it means there is at least a way to get very low level control of the display panel.
I have zero experience with kernel/ROM development but I can get technical so I did some (probably bad) research myself. Downloaded the kernel source from LG.
Found some interesting files here:
...\kernel\msm-4.4\drivers\video\fbdev\msm\lge\joan\
...\kernel\msm-4.4\arch\arm64\boot\dts\lge\
My guess is that V30's panel is "sw43402" (I think that's the driver IC model, same as 2 XL) - there are multiple files for it, with values for front/back porch, clk etc. which is what I suspect was modified for the refresh overclock.
Also found multiple entries/tables? for "gamma" and "blmap" (backlight map?) values which is what I hope can be used for a fix for the black crush.
My hope is that there is a way to tweak the gamma curves or some other form of display mapping. At 100% brightness my phone display is almost perfect, zero black crush. However as I set the brightness lower the black crush amount varies (it's not linear or exponential, it's "jumpy") which looks like there is some sort of mapping trying to compensate.
I'd love to hear your opinion especially if you have any experience with this stuff or if you can forward this to someone you know could answer. I would appreciate if you can tell whether you think this is possible and whether what I found is on the right track. Thanks for reading all this.
Click to expand...
Click to collapse
The savitar kernel dev is still active and made a new kernel, tachyon kernel that is, but he remove the 80hz because it doesnt work on real life test. All the kernel for v30 have kcal btw (there are only 2 kernel which is ceres (or lunar or orion or any other name that the dev like to named before) by @zacharias.maladroit and tachyon ( or some other name that i swear i cant remember) by @darkidz555
---------- Post added at 02:03 PM ---------- Previous post was at 01:59 PM ----------
cLick1338 said:
Thanks for the reply.
KCAL seems to be a step in the right direction however I don't think I can find any kernel for V30 that has it. I'll look into KLAPSE but it seems that it won't help "out of the box" without some lower level modifications.
Refresh rate - sure it may not be very practical but I don't think it's that dangerous (One example being the overclocked Note 3 displays in the Oculus DK2 back in 2014). 80Hz may be too much (and may be ghosting) but even 67-72 should make a noticeable difference. And why not have it as an option - for science - or for people that plan to upgrade soon and want to go crazy with it.
Can you please expand on this? What about the files I mentioned? An example snippet from
dsi-panel-sw43402-dsc-qhd-cmd-dv2_0.dtsi
Code:
[FONT="Courier New"]...
&mdss_mdp {
dsi_sw43402_dsc_qhd_cmd_dv2_0: qcom,mdss_dsi_sw43402_dsc_qhd_cmd_dv2_0 {
qcom,mdss-dsi-panel-name = "SW43402 cmd mode dsc dsi panel";
qcom,mdss-dsi-panel-type = "dsi_cmd_mode";
qcom,mdss-dsi-panel-framerate = <60>;
qcom,mdss-dsi-virtual-channel-id = <0>;
qcom,mdss-dsi-stream = <0>;
qcom,mdss-dsi-panel-width = <1440>;
qcom,mdss-dsi-panel-height = <2880>;
qcom,mdss-dsi-h-front-porch = <92>;
qcom,mdss-dsi-h-back-porch = <48>;
qcom,mdss-dsi-h-pulse-width = <32>;
qcom,mdss-dsi-h-sync-skew = <0>;
qcom,mdss-dsi-v-back-porch = <25>;
qcom,mdss-dsi-v-front-porch = <10>;
qcom,mdss-dsi-v-pulse-width = <1>;
...[/FONT]
I'd imagine something should happen if these are modified, or do you think nothing would happen? Some gamma and blmap tables are also further down in the file.
However there are multiple similar files in that folder which is a bit confusing to me. Any clue if there's public documentation on this or at least what to search for to understand it further?
Click to expand...
Click to collapse
Btw, @zacharias.maladroit motto for kernel development is stability and longevity so asking him for OC is not possible

Quick update, tried KCAL, only helps a little bit, but even on the most extreme settings it's barely effective.
KLAPSE has no means of improving it but I'm thinking something could be done by using the "brightness based scaling" and unlocking the "dimming" function to be able to actually brighten the image too. Currently it only goes from 20% to 100%, so it has to be able to go over 100% which I'm not sure is easy or possible.