LCD backlight probe fails on boot but not on restart

[xthezealot]

I enabled the pommed.service but it fails (only) after boot:

E: sysfs backlight probe failed, no fallback for this machine
E: LCD backlight probe failed, check debug output

But if I systelctl restart pommed, pommed starts and runs good.

Otherwise, when nvidia-bl is installed (with apple_bl kernel module disabled), pommed does not crash after boot but the screen backlight Fx keys (and only them) have no effect.

PS : Et merci pour le travail fourni jusqu'ici ! 👍

[bytbox]

Which version of macbook do you have? It sounds like pommed is starting before apple_bl is done initializing, right?

(This sounds eerily familiar, like there's already a similar bug report.)

[bytbox]

Ah, this is superficially similar to #24. Not sure the same hack will work though.

[xthezealot]

Yes, I think I also have a race condition.
With which unit(s)? I don't know. I have 5 different active units having "backlight" in their name.
What I know is that pommed has been successfully launched by systemd once in ~10 reboots, without any correlative config change.

Now, it's weird that I can't manage to defer the launch of pommed.
I edited the service file with

[Unit]
After=multi-user.target

or even a dirty

[Timer]
OnBootSec=60

and pommed still failed several seconds before the user login prompt.

My setup

• MacBookPro7,1
• kernel 4.8.13-1-ARCH
• pommed 1.50lw

[xthezealot]

It works!®

I reinstalled nvidia-bl but this time, I uncommented the "options" line in /etc/modprobe.d/nvidia_bl.conf.
Disabling apple_bl kernel module was not necessary.

For the record, I also replaced nouveau with the proprietary Nvidia drivers (but I don't think it's related as pommed.service still failed after this).