[KERNEL][4.4.302] Swan2000 Kernel for the LG V20

[ROMSG]

Since I don't play any games anymore on my phone since Clash Royale many, many years ago, the most intensive thing that I do it's occasionally video-calling via Telegram FOSS. But let me tell about my history with this V20 H990DS

I bought this device used, and the seller said that the battery needed to be replaced, and randomly it gave me green-screen reboot messages when below 30% and the thermals wasn't great because it was the end of summer here in Brazil. Since everywhere that I searched about buying new LG batteries anyone tells that it's hard to find a real original and reliable I decided to try this one from Aliexpress, and also ordered some copper shims (0.5mm and 0.6mm) to put thermal paste and improve things. And a 128GB SDcard since it was cheap now (compared to years ago... I tested with H2testw and it works perfectly)

So the battery arrived first, and even before it arrived I installed the Lineage 19 and with the new 4.X Kernel it almost never gave me more green-screen reboots, but few random reboots when below 35%.

With Lineage 18 + SwanKernel Extreme gave the most stable scenario but only one time I did try to video-call with Telegram and it went stable, but slow (probably due underclock, maybe?)

But last Friday using the new battery I tried to video-call through Telegram some relatives that live abroad, and with only 5 minutes of calling it rebooted and was warm-ish? So the copper shims arrived early that week and I decided to do the thermal mod this week.

With the 0.6mm it pressed the LCD giving a darker spot, so I decided to replace with the 0.5mm, put new thermal paste and try again... So no dark spot on the screen.

I installed Telegram on other computer and tried to call and test the V20, but it still reboots after some time, but the strange thing it never reaches 62 or higher.

I tried the CPU Throttling Test to test the thermals and it barely reaches 60 with the Extreme+Gaming or with only Extreme as well.

So after all of this, I remember that H990DS have the reputation for drawing a lot of power:

1) Even a "compatible non OEM" battery can't provide what this device demands in terms of power consumption?

2) Having a dual-sim gives me freedom in terms of separate personal-work calls etc and not having to carry 2 phones. Could a dual sim card adapter could be a better approach?

3) There's a chance that this H990DS motherboard it's problematic/defective somehow and replacing with another H990DS would fix things (or even a H990 non-DS with that dual-sim adapter)?

4) The random reboots could give some useful information somehow for you devs? And how the best way to collect it?

5) Are video-calling that demanding, even if it don't reach the same temperatures that the pure CPU stress?

6) Any tips, suggestions?

Thanks!


PS: @xxseva44 sorry I couldn't give you the logs, but the instability/problems here are taking much more time that I initially planned.

Try using smartpack kernel manager (root required) and set the CPU frequency on the big cores to 1.8ghz and 1.5ghz on the little cores. The H990DS variant in particular tends to have higher peak power draw than other variants in situations where cell reception is poor. Which can cause instability. Underclocking the CPU seems to help.

 

[AShiningRay]

Battery questions

First of all, have you checked the battery's capacity and general data through AccuBattery or another similar app? It's a good way to see if the voltages and current are right.

Charge it 5 or so times from 20% to 80% (though charging anything more than 50% should work) and see what it reports on battery health, assuming you didn't do that already of course.

 

[dextructor]

set the CPU frequency on the big cores to 1.8ghz and 1.5ghz on the little cores.

I did that and I couldn't tell from my type of usage that I noticed any slowdown on my device, but unfortunately didn't "solve" the issue. Underclock can help to consume less battery and I'm using the Extreme variant of this Kernel that should be undervolted , but thanks for the suggestion.

First of all, have you checked the battery's capacity and general data through AccuBattery or another similar app? It's a good way to see if the voltages and current are right.

Charge it 5 or so times from 20% to 80% (though charging anything more than 50% should work) and see what it reports on battery health, assuming you didn't do that already of course.

I've heard of AccuBattery in the past, but never really installed until now.

Well of all 3 batteries that I have (1 OEM and 2 from Aliexpress) only the OEM can really charge to 100%, the others varies, sometimes using chargers from LG, Samsung (that it's compatible with QC 2.0) and a plethora of cables the batteries reaches 70% to 85% and stop charging.

I installed the AccuBattery Pro and tested in different scenarios from the CPU Throttling Test consuming ~1400 and with AnTuTu Stress reaching ~2050, but after a while stabilized in ~1400.

When tested with video-call with Telegram the measure from AccuBattery was ~2300 even 2415 and dropped eventually to ~1900.

So this H990DS can't handle this type of power consumption, the battery that's the culprit? Or just "bad luck" in general?

 

[AShiningRay]

More battery questions

One way of checking if the battery is to blame is by letting AccuBattery measure its health after a few charges. A healthy battery has a capacity reading that's near its labeled capacity, and that is usually a good indicator that it can consistently supply the phone with higher levels of current.

 

[Draknodd]

Hi,

I did more test with the safe kernel variant to avoid the bcl throttling and get good performance.

First of all I set at boot with smartpack kernel manager:
1- max CPU freq 1998mhz
2- Disabled bcl running a sh script "echo disable > /sys/devices/soc/soc:qcom,bcl/mode"

In this way the CPU clock is not constantly throttled at 1036mhz (bcl is triggered despite the battery % and the battery is a 10000mah with health at 88% measured with accubattery)

The folkowing screenshits are the result with throttling test to check if temperatures are under control and the result of geekbench 6.
Compared to other lg v20 present in the geekbench database this result is above average (and very high is you consider that the phone is underclocked)
My theory is that the bcl is not reading the battery values correctly or it is not configured properly since with this setup I don't have any kind of reboot or sign of instability.

 

[AShiningRay]

*BCL tests*

The weird thing is that according to qcom's documentation, the way it is currently set up should throttle the phone once the battery reaches critical levels, if it is triggering no matter what and the battery in question is confirmed to be good, i think the most sensible explanation is that bcl behavior changed in 4.4, but qcom's docs weren't updated to reflect that (you'd be surprised with the amount of times this has happened before), because bcl reads from the same sensors your apps do, so what you see there is what bcl also gets.

I'll see if i can spare some time in the coming days to take another shot at BCL, something doesn't look right.

 

[Draknodd]

@AShiningRay Hi, I saw that you did more tweaking on the kernel (check on your github) regarding the BCL. Will there be a new beta release so that I can give some feedback?

Another thing that I noticed is that the GPU freq is stuck at 133mhz with the default governor. Setting the simple_ondemand governor with power level of 4 has reduced the animations lag and the freq now scales with the load. Do you know why this might happen?

 

[AShiningRay]

@AShiningRay Hi, I saw that you did more tweaking on the kernel (check on your github) regarding the BCL. Will there be a new beta release so that I can give some feedback?

Another thing that I noticed is that the GPU freq is stuck at 133mhz with the default governor. Setting the simple_ondemand governor with power level of 4 has reduced the animations lag and the freq now scales with the load. Do you know why this might happen?

Those BCL tweaks were pushed fairly late in the night over here (and G5+G6 only received it right now), so i didn't have time to actually build everything yet, but yes, there will be a new build soon... probably the last one before LOS 20 arrives, given how little has been changed on the kernel lately.

As for GPU frequency, that's definitely not normal, and also doesn't happen here. If it kept stuck at 133 with the default governor, it wouldn't rank on the upper echelon of msm8996 devices on 3dmark. What does happen is that msm-adreno-tz is fairly more conservative than simple_ondemand, so most UI tasks aren't enough to ramp the GPU up... we thought of increasing the minimum frequency to 214MHz in order to improve UI performance, but it didn't seem necessary for LOS-19.1 when the phone isn't bogged down by BCL, and also because the GPU is by far the most power-hungry processor on the phone, despite the CPU being the hothead.

 

[Draknodd]

Those BCL tweaks were pushed fairly late in the night over here (and G5+G6 only received it right now), so i didn't have time to actually build everything yet, but yes, there will be a new build soon... probably the last one before LOS 20 arrives, given how little has been changed on the kernel lately.

As for GPU frequency, that's definitely not normal, and also doesn't happen here. If it kept stuck at 133 with the default governor, it wouldn't rank on the upper echelon of msm8996 devices on 3dmark. What does happen is that msm-adreno-tz is fairly more conservative than simple_ondemand, so most UI tasks aren't enough to ramp the GPU up... we thought of increasing the minimum frequency to 214MHz in order to improve UI performance, but it didn't seem necessary for LOS-19.1 when the phone isn't bogged down by BCL, and also because the GPU is by far the most power-hungry processor on the phone, despite the CPU being the hothead.

I'll keep an eye on the releases on github then.

About the GPU that's actually nice to ear, I noticed that ondemand is really power hungry. I'll check the gpu frequency while doing some benchmark then. If I find is still laggy I could just decrese the powerlevel from 6 which is the default to 5 (I have a perfine 10500mah battery so a bit more of battery drain does not really concern me).

 

[AShiningRay]

06/17/2023 build is up!​

BCL should be behaving better now and random reboots will likely be far reduced in quantity (at least it is for the internal team including me), and if it isn't, there's not much else that can be done to mitigate it on the kernel, LGE's USB and power stack on stock is far too different and messy to feasibly implement on 4.4.

That BCL change will also show up on the next LOS build.

 

[Draknodd]

06/17/2023 build is up!​

BCL should be behaving better now and random reboots will likely be far reduced in quantity (at least it is for the internal team including me), and if it isn't, there's not much else that can be done to mitigate it on the kernel, LGE's USB and power stack on stock is far too different and messy to feasibly implement on 4.4.

That BCL change will also show up on the next LOS build.

Everything seems to be good with this build.
I'll stress the phone in particular when the battery is low (<30%) and report back!

 

[loyukfai]

Those BCL tweaks were pushed fairly late in the night over here (and G5+G6 only received it right now), so i didn't have time to actually build everything yet, but yes, there will be a new build soon... probably the last one before LOS 20 arrives, given how little has been changed on the kernel lately.

As for GPU frequency, that's definitely not normal, and also doesn't happen here. If it kept stuck at 133 with the default governor, it wouldn't rank on the upper echelon of msm8996 devices on 3dmark. What does happen is that msm-adreno-tz is fairly more conservative than simple_ondemand, so most UI tasks aren't enough to ramp the GPU up... we thought of increasing the minimum frequency to 214MHz in order to improve UI performance, but it didn't seem necessary for LOS-19.1 when the phone isn't bogged down by BCL, and also because the GPU is by far the most power-hungry processor on the phone, despite the CPU being the hothead.

Sorry for off topic, but do you mean Los 20 will be available soon?

 

[AShiningRay]

Sorry for off topic, but do you mean Los 20 will be available soon?

Nah, just that there aren't gonna be enough changes to the kernel to warrant another release before LOS 20... not that 20 is THAT far off, we're close but there's still a few minor things to iron out.

 

[dextructor]

I realize that when upgrading to the latest versions of Lineage there's a retention script that reinstall Magisk every time so I don't need to flash again after updates.

Did you or anyone on the team analyzed the viability of applying such methods to this custom kernel? What are the downsides?

I know that it's always a thing to balance: convenience and reliability, but I was curious about this topic.

 

[AShiningRay]

I realize that when upgrading to the latest versions of Lineage there's a retention script that reinstall Magisk every time so I don't need to flash again after updates.

Did you or anyone on the team analyzed the viability of applying such methods to this custom kernel? What are the downsides?

I know that it's always a thing to balance: convenience and reliability, but I was curious about this topic.

That's not possible on a kernel flashable for a variety of reasons. Magisk survives dirty flashes because its addon scripts aren't placed on /system or /boot, partitions that are usually overridden on a ROM update. The kernel on the other hand is that exact /boot partition once flashed.

So the only way to allow for a similar functionality for kernel zips would be to hard-code a path on /data where the flashable zip must go into, add that path into an addon.d script and make it so the script will only automatically reinstall the kernel after flashing a rom (how you would detect that a rom is being flashed and not another kernel or whatever, i don't know).

It's just too much work for little to no gain, with a risk of causing trouble for users on top of that.

 

[dextructor]

It's just too much work for little to no gain, with a risk of causing trouble for users on top of that.

I've imagined that wouldn't be worth the trouble, but since the lack of technical information about this topic wasn't very clear to me.

Anyway, thanks for the clarifications as always and the good job on the kernel

 

[Draknodd]

I'll stress the phone in particular when the battery is low (<30%) and report back!

Did a stress tests with 10% battery.. solid as a rock!

 

[FeNo2]

I have an H918 with stock/rooted 20h firmware. Last night I did a backup (thankfully) and tried to boot after installing this kernel and it seemed to hang at the pink Tmobile boot screen. I let it sit there for a couple minutes and nothing happened. I just did a restore and I'm back in business.

I used H918_v0.1-BETA8-Swan2000-Safe.zip

 

[ROMSG]

I have an H918 with stock/rooted 20h firmware. Last night I did a backup (thankfully) and tried to boot after installing this kernel and it seemed to hang at the pink Tmobile boot screen. I let it sit there for a couple minutes and nothing happened. I just did a restore and I'm back in business.

I used H918_v0.1-BETA8-Swan2000-Safe.zip

this kernel is for custom roms, Stock is not supported

 

[Black6spdZ]

Not sure it its OS or kernel related but the past few 19.1 builds and now even 20 has charging issues.. Anyone else noticed this?