[RPi4 1GB] LibreELEC 12 clash between WiFi and CEC

Hi,
I've seen people talking about issues with LE12 for WiFi and for CEC separately, but I haven't seen someone mention this issue.

If WiFi is connected AND CEC is enabled it will just crash constantly.. seemingly in about 30 seconds.
If WiFi is disconnected or Ethernet is connected and CEC is enabled things seem to work fine.
If WiFi is connected and CEC is disabled things (mostly) work fine - it might randomly freeze after an hour or two, or not at all.

How I discovered this:

I did a fresh install of LibreELEC 12.0 on a new SD card for a RPI4 (upgrading from a RPI3 I'd been using with LibreELEC flawlessly for years), and set it up, scanned the library etc with ethernet connected, but as soon as I tried WiFi the problems arose. I tried another install on a different SD card and RPI4, but was the same.

Then I noticed if I plugged the micro HDMI into the second port it didn't crash as often. But I needed CEC to work, so I changed the settings and the issues came back.
So I did those tests above to narrow down the issue.

When 12.0.1 was available I tried upgrading, and have subsequently tried a couple of the nightly builds, including the latest (LibreELEC-RPi4.aarch64-12.0-nightly-20240917-7de0439.img) in the hope the issue would be fixed but it still persists.

Thanks for the prompt response.

I did that and replicated the problem. That's pretty easy as it almost happens immediately - to the point I have to rush into settings to turn either WiFi or CEC off or I won't get a chance.

I did the paste system logs, there was two options - the crash log and normal so I did both.

Crash version:
https://paste.libreelec.tv/ethical-sawfly.log

Normal:
https://paste.libreelec.tv/proud-flea.log

Then I thought maybe I should replicate it with the default skin just in case.

Crash version:
https://paste.libreelec.tv/fluent-snail.log

Normal:
https://paste.libreelec.tv/stirred-rat.log

I noticed on the debug display when WiFi and CEC were both on the FPS would drop to 0.3, and the Kodi-CPU would shoot up to nearly 200%, and that is not even doing anything, just in the menu.

Thanks again.

Thanks for the suggestions. Will try them out.

Didn't realise just having those two things on would chew up so much memory.

I edited that line into config.txt and it stops it from crashing immediately. So I tried watching a movie - it froze about 18 minutes in, but then on the second attempt made it all the way through.

So, it seems manageable for now, so thanks again. Hopefully the root issue will be resolved in further updates, just wanted to raise awareness of it.

Thanks again for the response popcornmix, and for the detail.

Quote from popcornmix

It looks like from the log, the video that was playing when it crashes was using ffmpegdirect addon.

Do you get crashes when playing local content, or is it only videos using ffmpegdirect?

I'm not sure if ffmpegdirect causes significantly more memory usage.

No, there was nothing playing - that was my point, it was just sitting on the menu screen, or scrolling it. If you turn on both WiFi and CEC it will just freeze in less than a minute. So I thought there must be some conflict between them or some memory leak, because I didn't think they would use that much memory on their own.

The second lot of logs I posted where it crashed was just the default skin.

I'm not that concerned with play 4K content at this stage, in fact a lot of my files are only 720p.

Ok, I spoke too soon about the crashing seeming to have settled down - after I did the previous post I went to have something to eat so I turned on the TV and RPI, then went and got the "things I was going to eat" (not sure why the word for that is a censored word, but ok).

Came back and it was frozen on the home screen.
Rebooted and then tried playing a youtube video, and it froze a few minutes in.
So I guess I'll have to try some of those other settings.

Hmm good point. Is there a previous version of LibreElec (for RPI 4) you can recommend to go back to that doesn't have this issue of the WiFi using up all the memory?
I've been using LE on the RPI 3B for years without issue (currently on 9.2.8). Just thought if I was setting up a new one it would be best to go with the latest.

Thanks to all you guys for the help and the good work.

Ah ok. Well I wouldn't want to kill SD cards with constant read/writes.
The RPI 4 has higher specs, but the RPI 3B+ has had no issues with earlier versions, so I thought rolling back might help.
Just didn't know if there was a version where things related to that issue may have changed so I didn't have to trial and error it.
Thanks anyway. If I can't get an ethernet solution I'll try and test some things I guess.

Just an update on this after some further tests.
LibreELEC 12.0.1 works fine on the lower specced RPI 3B+ under the same conditions as above.
LibreELEC 11.0.6 works on the RPI 4 also with those conditions (although the occasional prompt for wifi pwd, which seems to be a known issue)

Both the RPI 3 and 4 have 1Gb RAM, and I haven't changed that cache setting, or anything else.
So it seems like the implementation of the WiFi code on LE12 for the RPI4 has some issues with memory leak/hogging.

Quote from Da Flex

I haven't seen such issues at the logs, so I assume LE 12 just uses more RAM. Unfortunately you don't want to fix it by creating a swap file.

But LE12 works fine on the RPI 3 which has the same amount of RAM. All I'm doing is reporting what works and what doesn't, I thought that was being helpful.
Destroying SD cards and having to reinstall the whole OS because of a software issue doesn't seem like a good solution, but maybe that's just me.

If I had a RPI4 with 2Gb of RAM and 1Gb of that was being used by WiFi I wouldn't think that was cool.