[Sony Xperia X Compact ROMs, Kernels, Recoveries, &] Spaceoid:
Phone still heating up randomly

I tested the new (and maybe last?) build of this ROM for nearly 72 hours now. Sadly the random heating up and battery drain problem is not or not fully fixed yet as it seems. I know, our beloved OP already declared that this build likely is the final one, but I will try to provide as much information as I can with this post and maybe he looks into it again or at least can point at something we users can do to prevent phone from heating and draining battery.

For the backgroud: The heating up happened twice for me in the last (nearly) 72 hours. The first time it happened yesterday evening, where I charged my phone up from 20 % up to 85 %. Up until 75 % battery capacity the phone charged normally, fast and stayed quite cool. Then I randomly took the phone in my hands as I received a message and noticed my phone was quite hot. I took a look into the battery graph and you could clearly see that after about 75 % battery capacity the phone randomly charged much much slower, which should be the point in time when also the heating set in. Sadly I did not take a screenshot yesterday. A reboot fixed the problem as always.

The second time the heating up happened this morning. I added a screenshot of my battery graph to this post (battery.png) and marked some points. As one can see, up until the RED line, my phone behaved totally normal. Constant battery level during the night, then normal usage with also YouTube, then I went for a run and did not use the phone for around an hour. Then I again did some stuff on the phone and again watched some YouTube, and randomly the phone started heating up and the battery level just fell off the cliff (starts at the RED line). I then stopped all applications, locked the screen and just let the phone alone for some time, to check if it was my usage that caused the problem (BLUE) line. As one can see, the battery did not drain as fast as before, but still more than usual while in deep sleep.

What always happens when the battery drain starts, is that my phone tells me that it is connected to WiFi, but has no internet connection. I added a screenshot of the symbol in my status bar, too (wifi_symbol.png). I live in a small flat and never had Wifi issues in here, also my girlfriend never loses the connection to the router. So it seems that the drain is somewhat related to wifi. To try that out, I disabled wifi (GREEN line in battery.png) and then re-enabled it again (VIOLET line in battery.png). As you can clearly see, the battery drain stops completely while wifi is deactivated, but starts again after wifi is re-enabled (I kept phone in deep sleep during enabled wifi, so the drain is not as strong). I then rebooted my phone and now it behaves normal again, even with enabled wifi.

What is ALSO curious is that during drain phases, my CPUs are super busy with something. I added a screenshot of that, too (cpus.png). Right now, without any use, the small CPUs of my phone switch between 400 and 1000 MHz with around 5% CPU usage, and the big CPUs stay at 400 MHz with 0 % usage. But, as you can see in the screenshot, during the draining phase, all small CPU cores were at around 40% usage at 1400 MHz, while one of the big ones always (!) was at 95% or more usage at 1800 MHz, so the whole CPU unit is super super busy while I as a user do not do anything with it. That also explains the drain.

I have no idea what keeps the CPU cores that busy. I saved a log that (if i read the log right) starts yesterday night and records all actions up until today noon. So, the start of the heating problem should be included, too. My phone started heating up somewhere between 11:30 and 12:00 this morning. I attached the log file to this post, too. I had to split it up into two parts because of file size. Maybe all this information helps. I would be super happy if the reason for this heating could be found, I understand though if you have more important things to do. If I can help you any further with that, just tell me.