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Snake Eyes problem after upgrading kernel to 4.19 on PI3B
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Snake Eyes problem after upgrading kernel to 4.19 on PI3B

by f1iqf on Mon Jun 10, 2019 9:42 pm

Hi !

I have a project running on a PI3B using Adafruit Snake Eyes (2 eyes option / IPS pannels).
It was working very beautifuly (on raspian stretch lite 4.14 April 2019 version) untill last weekend when I updated the PI (sudo apt update then sudo apt upgrade);
Then nothing was working any more (one eye was fine, second one very glitchy). Other things like sound were glitchy as well.

I tried on an other PI, with a freshly flashed sd card (still on raspian stretch lite 4.14 April 2019 version) without any other software, only the PI_Eyes software.
I was working fine. I did the upgrade again, and it stopped working again.

Then I redid the same : but upgraded the PI before and THEN installed the PI software : still bad.

Then I redid the same, but installed the updated packages one by one to find the one that is making trouble with adafruit pi_eyes software (installed one package, rebooted, etc).
The package causing problem is raspberrypi-kernel/stable updating the kernel to 4.19.42-v7+. I have complete logs of the work of the upgrade available if you need...

Some more information :
I can make the pi_eyes somewhat working by launching fbx2 at a much lower bitrate (previously I was using the default 96Mhz to now about 8Mhz ; it is less glitchy (but not perfect) however the refresh rate of the picture is so bad that I do not wish to use it (it is ugly).

I also took snapshots of the CPU usage of both processes "python eyes.py" and "fbx2" with both kernel versions :
sudo ps -p `pgrep python` -o %cpu,%mem,cmd

Kernel 4.14 (Working perfectly) :
%CPU %MEM CMD
74.7 3.4 python eyes.py --radius 240

Kernel 4.19 (not working) :
%CPU %MEM CMD
74.9 3.4 python eyes.py --radius 240

Now for fbx2: sudo ps -p `pgrep fbx2` -o %cpu,%mem,cmd

Kernel 4.14 (Working perfectly) :
%CPU %MEM CMD
112 0.2 /boot/Pi_Eyes/fbx2 -i

Kernel 4.19 (not working) :
%CPU %MEM CMD
29.6 0.2 /boot/Pi_Eyes/fbx2 -i


In conclusion, I think there is a compatibility issue between the fbx2 software (the process that is getting data from the screen and sending it using SPI to both screens) and the new Kernel 4.19. Especialy for the second SPI1 (SPI0 for the first eye seem to be perfect).

Can you please help me ?

Thank you very much in advance / Nicolas (New York/Manhattan)

f1iqf
 
Posts: 1
Joined: Sat Dec 11, 2010 8:36 pm

Re: Snake Eyes problem after upgrading kernel to 4.19 on PI3

by adafruit2 on Tue Jun 11, 2019 9:34 pm

our solution for now is just to keep running on 4.14 - burn a new raspbian with 4.14 and don't upgrade - linux breaks stuff a lot, upgrading will always cause breakage!

adafruit2
Site Admin
 
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Joined: Fri Mar 11, 2005 7:36 pm

Please be positive and constructive with your questions and comments.