probable general issue with toggles / battery, CPU overheating

[NeoTheThird]

This is a complicated one, I'm trying to reach a diagnostic with limited tools. I'll leave the rest with you. Here's the deal:

I have noticed that the toggle buttons seem to be "lying" or providing wrong information, as if when we disconnect / deactivate certain functions, they still seem to be active on the background until restart - Despite the toggle buttons showing them as "off".

Test examples:

• turn on cellular data
• turn on wifi
• turn on hotspot function.

Next:

• leave cellular data on (on 2G only, to test the connection speed and demand on the battery).
• turn off wifi
• turn off hotspot.

Results:

Battery goes down steadily (graphics on battery settings show a sharp drop over several minutes / hours) with no usage whatsoever, no running applications, only stand-by. In less than 2 hours it goes from 95% to 60%.
Temperature on the upper back of the phone goes up and keeps a very hot, steady temperature (not the battery, but the circuit on the top part, near the top antenna, so it could be the CPU, ram chip or the modem, I don't know), to the point where I have to remove it from my pocket, it's almost burning.

My theory:
a) the wifi hotspot could still be turned on, despite the fact that I apparently turned it off, along with the wifi connection. There's obviously no data connection at that point (can't find the wifi network), but the circuit keeps operating, I guess?

b) some processes could still be running on the background on a deadly loop, overheating the cpu / ram and consuming more battery than would be normal?

• Small clue: problem goes away after restart. -

This could be a battery or code optimization issue, or maybe a bug with the toggle functions, as it seems to pop up at specific events.
As you can see on other bugs, there seems to be a number of similar issues regarding activation / deactivation of functions / forced to restart to re-assume functions and so on. We need to check this with proper measurement tools and a full survey on running processes during specific test conditions. I don't have the skills nor the instruments to go beyond this first analysis.

Reported by https://launchpad.net/~mgc.lude.

[vadrian89]

Having this issue, along other hotspot-related issues on Nexus 5.
Basically after hotspot is turned off, battery draining increases.

[kwah-gh]

Looks like power management is a big issue on FP2.

What I observe: steady decrease of battery charge from 100% to about 50% in 12 hours with a constant rate. Enabled functionality is WiFi + BT only (BT is not actively used, device is on WiFi network, but there should be no active services that use it). Basically, device is idle all the time, since I am just testing new install and have not figured out yet how to transfer all relevant data from my current daily device to a new one. Extrapolating, device drains battery completely in 24hours, while in standby. Which is poor, since it will go down, when device will be also handling cellular connection later on.

Due to a screen bug, I had to opt for rc-channel, system reports now 15.04 (r13).

My daily mentioned above is BQ E4.5 on OTA2 and it seems to perform better with cellular enabled on top of WiFi and BT, and seeing more action compared to FP2.

[Flohack74]

I can confirm this high battery drain, unfortunately...

[kwah-gh]

It looks like there is a good progress on toggles part. I can see WiFi on/off on battery history graph (1 hour off vs. 1 hour on) or at least I think so ;)

WiFi module energy consumption is high, despite it is not actively used. What can be done to help in figuring out, what is going on here?

[Flaburgan]

I reproduce this on my FP2 every time.

STR :
1: charge the phone, "normal" mode
2: Stop charging, here the GSM is on, no data connection, no WiFi, no Wi-Fi hotspot, my normal usage
3: Toggle on Wi-Fi hotspot, that activates Wi-Fi, then toggle off both Wi-Fi hotspot and Wi-Fi, and even turn on flight mode, to be sure nothing is communicating, and screen stays off because no notification. As you can see, the battery is drying and the phone is becoming very hot.

FP2 isn't the only affected device, OPO also is affected.

[Flaburgan]

I'm currently running the new Halium 7.1 based port on my FP2 but unfortunately the hotspot not turning off is still there:

[gbdomubpkm]

This bug ''poisons'' obviously also the functioning of the ONEPLUS ONE. I suspect that the overheating is not triggered directly after the deactivation of the hotspot and the wifi but it creates a condition which makes that if one starts after these deactivations the flight mode, the phone starts to heat up, keeps a rather hot temperature and the battery empties gradually. So after each use of the hotspot, I prefer to stop the phone, to restart it after so as to remove this condition in the event of using the flight mode.
For an internet connection, the workaround is to use USB RNDIS connexion (via UTTT) : so no hotspot, so no nasty surprises regarding battery drainage !!