yashsingh1/xdaforums huggingface dataset:
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
Hi. You're kernel seems great and I may try it out :) I'm a new GS3 owner who came from using a galaxy S WiFi 4.0 (Basically a GS1 with WiFi only). There, some of our devs had added a 20% undervolt to the LCD in their kernels. This made a MAJOR difference in battery life since the LCD is the battery hog of phones. Do you think you could try adding that to your kernel? I feel like it's just a free opportunity to increase battery life if a dev here can try it out and implement it to a kernel.

I can provide links if needed to the kernel that had the UV in it. let me know what you think. :)
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
S3s use OLED screens, which are quite different from LCDs. Unlike LCDs, OLED pixels are directly illuminated by the current passing through them (or the voltage across them, if you'd prefer to think of it that way). Changing the voltage going to OLED pixels changes the brightness of the pixels. I know it's not what you're asking for, but you can already undervolt your screen, and you don't need a custom kernel to do it: just lower the screen brightness. :p

I'll see if I can tweak the voltage regulators, but I'm not optimistic. Depending on how the screen's circuitry works, reducing the voltage might reduce brightness, throw off color calibration, or cause artifacts at high brightness.

Could you link me to the kernel(s) that had support for this? I don't think think the changes will carry over to the S3, but I'm curious whether the devs needed to do anything more than tweak the voltage regulators in order to get it working.

Out of curiosity, did reducing the voltage on the LCD have any noticeable effects? I would think that reducing the voltage far enough would cause decreased brightness, longer response times, or maybe even outright ghosting.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
Thanks for your reply.

Here is the kernel that I used on my device. Sources are in the op. http://xdaforums.com/showthread.php?t=2356106

Here is a kernel on the 5 inch variant that also had the undervolt. http://xdaforums.com/showthread.php?t=2286381

Might be noteworthy that the kernel for the 5 inch says the touch screen itself is undervolted. I assume that's the same as the LCD (admittedly I'm not really knowledgeable on how phone tech works lol).

Take a look and check it out. That undervolt made a huge difference in battery life on the Galaxy player. I've heard that on some devices it won't work because it will mess up the capacitive buttons, but on CM you can disable those anyways and enable on screen buttons, and to me, that would be worth a much better battery life.

Also, there were no noticeable negative effects at all.

The kernel DID allow us to lower our screen brightness below stock minimum (why does Samsung make the minimum brightness so high compared to iPhone?), but I'm not sure if that was a result of the undervolt or of the tweaks intended for it. Either way it wasn't a problem and was actually something the users (myself included) wanted.

Speaking of screen brightness, I'd love to be able to lower it on the S3 beyond what Samsung made the minimum lol. Is there any way to do that without an undervolt or kernel tweak on this device?

Thanks :)
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
I'm not terribly familiar with the innards of the Galaxy Player. It's possible that its screen shares a regulator with the touchscreen and/or the capacitive buttons. On the S3, for the most part, everything has its own voltage regulator, so you can control the voltages of each piece of hardware independently. There shouldn't be any issues with breaking the capacitive buttons by undervolting.

I'm sure there's a way to adjust the minimum brightness, but I haven't looked hard enough to find it. No matter how many times I go through the code that configures the screen for new brightness levels, I can't make sense of it. :(

I'm a bit sidetracked by a bizarre (and sort of fascinating) issue another user is having, but I did play with the voltage regulators a bit last night. Lowering the display's voltage doesn't seem to cause many issues, but it does throw the screen's gamma way, way off. Bizarrely, the screen actually appears brighter (and also a bit washed out) with lower voltage. I have no idea (yet) how battery life is affected.

The code is pretty sloppy at the moment, but I can clean it up and send you a build if you're interested.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
Okay. Maybe someone has figured out the minimum brightness thing and I can search around for it.

Is that so? Hm. How much did you undervolt it? Did the gamma correction get worse as you undervolted more?

I am definitely interested in seeing if the screen could be undervolted on the S3. If I can be of any help with it, send it to me. However, I can't say my curiosity really cares too much to see it if there's no help to be given. I'm just set on the goal, and that is undervolt the screen and save a noticeable amount of battery like on my previous device :)
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
I added a setting so I could change it on-the-fly. I tested from 3.1v (stock) down to 2.5v. The gamma gets progressively worse as the voltage decreases.

Aside from the incorrect gamma (which can mostly be worked around using the gamma controls anyway), the screen doesn't look half bad. I really expected to see much worse side effects.

I'm going to take another look at the brightness code, since it also handles color calibration. It might help figure things out.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
Wow, that's very interesting. Keep me updated on how that goes and also let me know if it makes any noticeable difference in battery life.

In case this is useful at all, this is an old GS2 kernel that actually undervolted the screen AND ram "under voltage -> RAM(1.8v to 1.6v) and LCD(3.3v to 2.4v)" Perhaps the info and sources may be useful to you. http://xdaforums.com/showthread.php?t=943669

Also, want to ask one more thing of you and your kernel. Not sure which rom you use as your daily driver, but I'm currently using CM11 M12 (snapshot). I love CM and it is working great (admittedly, I haven't really tried anything else), but I'm sure you're aware of the notorious camera problem that, to my knowledge and according to my research, all AOSP GS3 roms have for whatever reason. I am dealing with it myself and am considering going back to stock rom because it's so annoying. The CMfix and restart.apk method doesn't even work for me. On one of the GS3 variants, a kernel dev claims to have fixed it. Was wondering if you might be interested in looking at that and seeing if you could put that in your kernel. This is the kernel http://xdaforums.com/galaxy-s3/orig-development/28-04-googy-max2-kernel-2-3-1-cm-camera-t2517875.

I even tried flashing a zip that changed some camera libs and replaced the camera app, and I still have the problem. It's very odd. I may even try reflashing CM11 to make sure the problem remains. Did you have the problem and work around it in any way?

Sorry the new guy is suddenly coming in here and throwing ideas at you :) I was browsing kernels and yours is very minimalistic and practical (which is what I like), so I can't help but want to suggest more practical features :P
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] :
Actually the gamma control needs a lot of work. It needs to be fixed for cm 12.1, where livedisplay expects gamma control to start at 100% and go down only, not up and down like ours. I merged a patch to allow for our gamma control but it's still pretty ****ty. I had an idea to use the lower edge of gamma control for brightness (so brightness settings below a certain amount actually become an automatic -10 to R, G, and B together). I think I'm telling you this so you'll code it so I can kang it ;p
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] thejust:
Have you tried open camera from the playstore? I heard the issue is with stock camera app.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
I have not but I can. I don't think it's the camera app though. I have Google Camera as well and when the camera crashes in any camera app, all camera apps will then come up with some sort of "Can't connect to camera" error until reboot.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] thejust:
Yeah it'll do that lol,I had the same issue before and have not had any issues with open camera. pictures and video work great now.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
New builds are up. I was playing with the toolchain I use for dkp, and discovered a handful of interesting optimization possibilities. Everything seems stable, but it's possible that some new issues will pop up with the new optimizations.

Changelog:

Synced 5.1 with CM

Updated to BFQ v7r8

Reworked some hotplug infrastructure in preparation for a project I'm planning

Overhauled auto-hotplug: it's now more efficient and much more aggressive

Enabled -ftoplevel-reorder, allowing LTO to do a better job optimizing

Specialized some LTO behavior to further improve optimization

Added a few smaller optimizations: inlined spinlocks, improved optimization for CPU hotplug, etc.

Normally, I'd just describe optimizations as "...and I optimized some stuff," but I'm pretty excited about the new optimizations in this build. The benchmarks I usually use to evaluate changes are all showing 5-10% improvements, and battery life over the past 24 hours has been noticeably better. Not too bad, considering how little I actually changed. :D

Battery life wasn't noticeably different with the screen undervolted to 2.5v. I need to play with that code some more, but I'm doubtful that it'll suddenly start making a difference in battery life. :(

I certainly don't mind suggestions. :) Just keep in mind that changes that work well on one device may not work well on the next. Even the international S3 (i9300) is very different from the US S3, so many changes won't carry over.

The more I look at that code, the less I want to deal with it. :(

Where's Luis been lately? He seems like the guy you want working on that.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] gvsukids:
Are the optimizations already in place, or do we need to implement them?
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
Baked in, no need to do anything.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] whodisname:
Working great on d2att cyanideL NJ1.

Didn't even have this upgrade apps after flash. I won't comment on battery cuz I have a 4200mah and it always lasts all day. Always.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] canodroid15:
giggady giggady! ???
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Hmm... maybe it's time for me to try out dkp again. Maybe the increased wakelocks I was getting before will have magically resolved themselves.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
Really? hm. That leaves me baffled a bit. Surely if the screen is using some 40-50% battery, then a ~20% undervolt should change the screen battery usage to 30-40%,right? Unless I'm missing something and there's more to the screen usage than just the voltage.

I do appreciate your interest in this though and that we are at least trying :) To me, a mobile device ought to be as mobile as possible, so I'm a battery saving junkie.

BTW I'm using the new kernel build and I'm liking it. I was having freezing problems with the previous build that seem to have gone away with this one. Keep up the good work :thumbup:
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] critikality:
wooo!! you nailed it again [MENTION=4932679]decimalman[/MENTION], latest kernel running even more smoother and battery performance has really jumped up. I have no idea about the coding involve, but kudos for updating BFQ scheduler and all the revamped goodies baked in.

One KEY FEATURE why never look back, on this kernel is: The device stays too cooler even on 3g. Thanks so much for your hardwork.

ROM: Cyanide L (Super Daily Driver)

Kernel: dkp kernel (Always Latest)

Gov/Sch: Freelaunch / BFQ
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
It's worth a try, anyway. Let me know if it's working any better.

I don't know what the deal with the screen is. For simple hardware, reducing the voltage will use less power, as you'd expect. Unfortunately, the screen doesn't seem to be simple hardware. :(

I haven't heard much about freezing lately (except for another user with a temperamental CPU). If you run into it again, send me a last_kmsg.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
I've encountered a couple freezes the past couple days. I don't recall exactly how long I was using the default CM11 kernel, but I don't remember ever getting any freezes on that. I tried to get the last_kmsg...but last_kmsg doesn't seem to exist. To my understanding, a last_kmsg should just be right there in /proc/, right?

There is a kmsg, if that's for some reason the same thing.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
As long as there's a last_kmsg saved in RAM, /proc/last_kmsg will be there. Pulling your battery is guaranteed to erase it, and sometimes it just decides to disappear on its own. Usually, holding the power button to reboot will leave it intact.

/proc/kmsg is different. last_kmsg is the log from the previous boot, kmsg is the log from the current boot.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
Okay. For whatever reason, the last time I checked after a freeze up it wasn't there, and I just held down the power button like I usually do...Anyways, it's showing up now. Had two freezes today, one with the screen off and one with it on. Both required me to force reboot by holding down the power button. msg2 is the one with the screen on, and msg is the one with the screen off.

I'll see about reverting to the default CM kernel and using that again for a bit to ensure it isn't just your kernel.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Just wanted to say that I haven't been getting the wakelocks with the most recent version of dkp that I had before. Not sure what changed, but battery life has been great on this build. Nice work.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] Rickymills:
What is your kernel setup like? CPU etc
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Nothing fancy. Just running Intellidemand governor with zen scheduler.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
Thanks for following up. :good:

last_kmsg sometimes just doesn't show up. It's fussy like that.

Hmm. Those logs look awfully familiar, but the issue that used to cause that should have been fixed long ago. I'll take another look, since apparently it's still broken.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] critikality:
Happy Father's Day to you [MENTION=4932679]decimalman[/MENTION] for your invaluable time, energy and everything put into making this wonderful kernel for us all. Thank you and good work done.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Hey decimalman,

I noticed a ton of various kernel commits for the d2 in the recent CM12.1 nightlies. Are you planning on posting an updated build in the near future? I'm running your latest kernel with an older CM12.1 nightly with no problems, but I was just wondering.

Thanks for all that you do.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
In good time. :) I'm struggling with a bizarre bug at the moment. I guess I should just stop breaking things, huh? :laugh:
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Hey, man. "Go big or go home" I always say.

Those few changes you made for the last build had measurable results in terms of battery life. I was very impressed. Looking forward to your next release. :good:
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
I'm working on rewriting the code that those changes touched. While the last build was encouraging, the changes were awful and self-limiting, and I can't make any further improvement on them. The rewrite should allow me to push a bit further.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] WHib96:
[MENTION=4932679]decimalman[/MENTION] Have you any updates on the problem that was showing up in my last_ksmg?

Also, just out of curiosity, have you toyed around anymore with under volting the screen?

Keep up the good work :)
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
There are a few possible causes for what you're seeing, and I'm not entirely sure which one to blame. Next time I update, I'll add a few new settings to help track down the issues that you and a couple other people have been seeing.

I played with undervolting the screen a bit more, but I haven't gotten anywhere. For the time being, I'm giving up on it. I'll keep it on my list of interesting projects to revisit later.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] SpiderNhan:
The latest CM12.1 Nightlies 06/xx-07/05 seem unstable with dkp 06/08 build. I'm also running Xposed, so that may be the culprit, but it always seems to crash on me while using Facebook Messenger. I get better battery life using dkp, so I test it every other build. Love your work [MENTION=4932679]decimalman[/MENTION]. Looking forward to the next build.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Ditto. ;)
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Just out of curiosity, which governor/scheduler combo has everyone settled on for dkp?

I'm currently rocking Tierservative with fiops, but I used to run an Intellidemand/Zen setup for a long while.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] tdotdot:
Woo new DKP out!
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
What? Where?
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] tdotdot:
Ah shoot I thought July was the 6th month. Ignore lol.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Aw, man. You got my hopes up. :p
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] htc_softbank:
I found out an issue with this kernel!

I noticed it doesn't charge my anker 7200mA battery properly.

When I charged the phone overnight it would show 100%, but immediately drop to 80% or 60% (unpredictable) once unplugged from the charger.

If I plugged the phone in to charge again it would properly charge to 100%.

Definitely a kernel issue since I reverted back to base kernel on cm 12.1 official and all is well again.

Just wanted to share in case anyone uses anker battery and thinking of going custom kernel.

Also hoping this can be fixed so I can try to flash and test it again.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] critikality:
Am pretty sure [MENTION=4932679]decimalman[/MENTION] is working very hard to revamp our lovely kernel, thanks Sir for your invaluable time, energy n money you put into making this juice for us here. Long live dkp Kernel!
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
Forever and ever, amen.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] htc_softbank:
Actually, the issue is the Rom, not the kernel. (Doh, sorry about that)

It seems that when my battery is close to 0% and I charge it overnight, the Rom thinks that the battery is fully charged when it isn't.

I checked the phone the other morning when it was still connected to the charger and it showed 60%. After unplugging it, it jumped to 100% and quickly dropped back down to 60%

Anyhow, I just wanted to follow up since I made a mistake thinking it was the kernel when it isn't!
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
So dkp is embarrassingly out of date, and I haven't dealt with any bug reports in the last month and a half. Oops. :( I haven't been working on dkp as much lately, and when I do, I'm hung up on improving the optimizations from the last build. I haven't gotten very far with that, so I'm putting it on hold to get a new build out. Not a lot has changed on my end, but there's new builds up on Mediafire.

Changelog:

Synced 5.1 with CM. The new screen color controls are supported, and there's been plenty of other updates as well.

Switched to a shiny new toolchain based on GCC 5.2. Performance seems similar, but it's making much smaller kernels.

Added an option to disable standalone power collapse. See below.

Added new builds that disable dkp's optimized spinlocks. See below.

Changed some build settings to take advantage of GCC 5, improve optimization, and make dkp easier to build.

Probably some other stuff, but it's been ages since the last build and I don't remember.

The standalone power collapse and spinlock stuff is to help track down a few issues. If you aren't getting random freezes/reboots with the previous dkp builds, you don't need to worry about this stuff; just flash the regular (not "revert-spinlock") builds as usual.

If you've been seeing random freezes (possibly with a black screen and/or tons of lag right before), try flashing one of the revert-spinlock builds. Whether or not it helps, please let me know.

If you've been seeing random reboots, try disabling standalone power collapse. I'm not sure it's the actual issue, but it's worth a try. To disable SPC, either open /sys/kernel/dkp/spc_enabled and change the "1" to "0", or open a terminal app and enter "su", followed by "echo 0 >/sys/kernel/dkp/spc_enabled". If it helps, let me know and I'll figure out an easier way to disable it.

Finally, there have been several bug reports involving the battery/charger stuff. I don't see any differences between dkp and CM that would cause it, but I'm going to take a closer look when I get a chance. If I find anything, I'll send out some test builds.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] manfromgta:
Flashed on d2att running PAC rom. Will report any findings after testing.

Do you have any recommended governor/scheduler combo just for moderate use.

Thanks slot for your contribution. :)

Sent from my SAMSUNG-SGH-I747 using Xparent Cyan Tapatalk 2
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] canodroid15:
? its about dang time...SHEESH! LOL! JK? thanks decimalman! You rock bro
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] manfromgta:
[MENTION=4932679]decimalman[/MENTION]

Testing of the (normal) 07/25 has been successful on d2att running PAC. No RR's or over heating. Battery drain is normal. Device sleeps like a baby.

Governor/scheduler: free lunch/fiops. The rest of settings are default.

Thanks for the contribution. Well done! :)

Sent from my SAMSUNG-SGH-I747 using Xparent Cyan Tapatalk 2
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] ScOULaris:
New dkp! Will report back with impressions soon.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] elcocolo50:
I flash the new dkp-aosp51-revert-spinlock-51-d2-20150725 have no problem,,my galaxy s3 run great, no heating,
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] tdotdot:
Same, flashed it on 24th nightly of PAC, runs great haven't had anything weird so far.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] whodisname:
On mobile? Can't download kernel?

http://www.speedproxy.co.uk
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] whodisname:
Yep, revert spinlock. I believe I can finally use CyanideL as a daily driver. Used both kernels, revert spinlock is the one. Double digitax max temp. decrease.

Thing used to get hot through my pants pocket and almost burn me like an apple watch!! Not anymore.

Thanks, dude! I don't even care that it took you a short while ;)

D2att

MJ1
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] decimalman:
Interesting. That means there's still bugs in the optimized spinlocks. I'd like to figure out a fix for them, since they're good for performance. Can I send you a build to try when I think I've fixed them?
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] whodisname:
Yep. You send it, I will run it. Not a problem.
[AT&T, Rogers, Bell, Telus Samsung Galaxy S III] emilakd:
Link dont work . please repair