flipping frames bug and workaround

[zetabeta]

flipping frames bug and workaround

for mobian phosh with kernel 6.1.
https://barrelmem.s3.eu-north-1.amazonaw...ingbug.mp4

i have concluded at this point that this bug is in two parts, powersaving part and frequency change part. practically all gnu/linux distributions and plasma and phosh are affected.

powersaving part seems to be more straightforward and more rare. this can be avoided by following.

Code:

# udev rule
KERNEL=="1c40000.gpu", SUBSYSTEM=="platform", DRIVER=="lima", ATTR{power/autosuspend_delay_ms}="-1"
KERNEL=="1c40000.gpu", SUBSYSTEM=="platform", DRIVER=="lima", ATTR{power/control}="on"

powersaving part is harder to replicate. you need some screen activity with some networking activity and possible cpu activity, it is not immediate.

frequency change part can by avoided by following:

Code:

# udev rule
KERNEL=="1c40000.gpu", SUBSYSTEM=="devfreq", ATTR{min_freq}="432000000"
KERNEL=="1c40000.gpu", SUBSYSTEM=="devfreq", ATTR{max_freq}="432000000"

however, in my situtation, frequency bug happens only in 1.2a hardware version and not in 1.2b. so i don't rule out possible hardware problem in 1.2a version or my specfic individual phone.

if you tech savvy enough and you have pinephone regular. could you test frequency part of this bug and say your hardware version (1.2 1.2a 1.2b etc). you only set powersaving part, then run glxgears in user interfaces without auto suspend, sreenlocks and screen saving. then run following script in background.

Code:

while true
do echo 432000000 > /sys/class/devfreq/1c40000.gpu/min_freq
echo 432000000 > /sys/class/devfreq/1c40000.gpu/max_freq
echo 312000000 > /sys/class/devfreq/1c40000.gpu/max_freq
done

generic copy paste:

Code:

# udev rule. this prevent flipping frames bug
# example file location /lib/udev/rules.d/98-preventflippingbug.rules
# powersaving part
KERNEL=="1c40000.gpu", SUBSYSTEM=="platform", DRIVER=="lima", ATTR{power/autosuspend_delay_ms}="-1"
KERNEL=="1c40000.gpu", SUBSYSTEM=="platform", DRIVER=="lima", ATTR{power/control}="on"
# frequency part, may not be needed
KERNEL=="1c40000.gpu", SUBSYSTEM=="devfreq", ATTR{min_freq}="432000000"
KERNEL=="1c40000.gpu", SUBSYSTEM=="devfreq", ATTR{max_freq}="432000000"

log file is for mobian phosh.