Librem 5, hotspot and temperature

[veleno]

Hi, few time ago I posted screenshots about my burning L5 (around 60 degree C) without understanding why!! Now I discovered that’s when I use hotspot!!
Is it a bug? Any idea how to solve it?
I literally can’t handle it because so hot!
Thank you

[FranklyFlawless]

@veleno

Any idea how to solve it?

Turn off hotspot so the Librem 5 does not produce hot spots.

[veleno]

ahah of course! I turned it off and in fact temperature now is regular (48cpu) but what if I need to use my L5 as hotspot?

[FranklyFlawless]

Wear (high) heat-resistant gloves.

[veleno]

Well, maybe it’s just my paranoid but I’m scared to damage it if I use hotspot for long session (other than to be impossible to handle it)!
Do you think is there a way to set a max limit temperature in some way (settings) or maybe there will be a fix by Purism in next updates (Crimson)?
I don’t have wifi at home so, usually, I use hotspots as substitution of it!

[FranklyFlawless]

@veleno

Do you think is there a way to set a max limit temperature in some way (settings) or maybe there will be a fix by Purism in next updates (Crimson)?

It is possible to create/modify trips/triggers for CPU/GPU thermal throttling:

@dos

The CPU is set to start thermal throttling at 50°C - first by limiting the frequency to 1.0GHz, and then starting at 60°C by idle injection. Additionally, the GPU gets throttled at 65°C as well. The critical temperature at which the SoC is forcibly shut down is 90°C (I have hit that in the past on devkit and some early batches when compiling some big stuff, but so far never on Dogwood or Evergreen). These values are set in the device tree: https://source.puri.sm/Librem5/linux/-/blob/pureos/byzantium/arch/arm64/boot/dts/freescale/imx8mq.dtsi#L285

Thinking about your situation in more detail, here are a few ideas you can consider to improve it:

1. Replace your battery with a fresh one in the chance it is defective.

@fiacco

@irvinewade

Should be easy enough to get a spare battery (from Purism) and fault isolate to see whether it makes a difference.

I do have a spare battery. I replaced it and temperatures have dropped

2. Remove the bumper case.

@dos

Oh yeah, I’d definitely not use a bumper case when the phone’s docked. It’s exactly the opposite of what I was suggesting above with the fan

3. Backup any important files/folders, then reflash the Librem 5.

@veleno

ok! found that system process is locked on 100% and RAM and Swap 99,9%
L5 hot and unresponsive (I tried to open terminal and digit: sudo kill -9 (system pid)) to see what would happened but L5 totally unresponsive! I had to switch off it forcing pressing power button.

[raenrfm]

Ever since I have enabled ZRAM on my phone it runs better and cooler.

[nerd7473]

Gonna be setting up ZRAM soon on my device

[weirdnerd]

Can you replace some hotspot use-cases with USB tethering? That will probably not produce as much heat.

[j_s]

@veleno

ahah of course! I turned it off and in fact temperature now is regular (48cpu)

The L5 obviously needs a coldspot app.

[veleno]

Coldspot app is an app to monitor L5 behaviour?

[j_s]

Coldspot is an app to inject cold into the L5. (It was a joke.)

[FranklyFlawless]

Let us know if any of my three suggestions leads to thermal performance improvements on your Librem 5.

[veleno]

Honestly, when I read your post, I asked to ChatGPT and here the answer:

Me:
What’s cold app referred to digital devices (smartphones, PC,…)?

ChatGPT:
In the context of digital devices like smartphones and PCs, a “cold app” refers to an application that is not currently running in the device’s memory and needs to be fully loaded from storage when launched. This situation is known as a “cold start.”

Key Points about Cold Apps:

1. Cold Start:

   • Definition: The process of launching an app that is not already running in the background.
   • Behavior: The app must load all its necessary resources from the beginning, which can take more time compared to when the app is already in memory.
   • Implications: This can lead to longer loading times and higher initial resource usage.

2. Warm Start:

   • Definition: When an app is resumed from the background where it is still held in memory.
   • Behavior: The app can resume quickly without needing to reload all its resources.
   • Implications: Provides a faster and smoother user experience.

3. Performance Considerations:

   • Memory Management: Operating systems often manage memory to keep frequently used apps in a “warm” state to improve performance.
   • User Experience: Cold starts can be noticeable to users, especially for resource-intensive applications that take longer to initialize.

Examples:

• Smartphones:

  • Cold App: An app that you open after restarting your phone or after it has been fully closed (e.g., swiping up and off the screen on an iPhone).
  • Warm App: An app that you switch to from the background, like switching between running apps using the recent apps button.

• PCs:

  • Cold App: A program that you open for the first time after booting up your computer or after closing it completely from the task manager.
  • Warm App: A program that you switch to from the taskbar where it has been minimized.

Managing Cold Apps:

• Optimization: Developers often optimize the startup sequence of their applications to reduce the impact of cold starts.
• Caching: Some apps may cache certain data to speed up cold starts, even though the app itself is not running.

Understanding the difference between cold and warm starts can help in both optimizing application performance and improving user experience on digital devices.

[irvinewade]

I guess that shows the current limitations of ChatGPT i.e. no sense of humour - although technically your prompt was wrong i.e. you asked the wrong question (“cold” should have been “coldspot”).

[raenrfm]

Humour will be the last thing that AI will be able to even come close to replicating.