Backlight on HP Envy is dimmed on boot

tancrackers · 2012-10-14 07:00:36

HP Envy 15 3040nr
I have to turn my brightness up everytime I boot, despite having my brightness settings turned up all the way.

teateawhy · 2012-10-14 10:40:43

Please add more information about your Desktop Environment.
Edit: I read from another thread you created, you are using Gnome 3.
Now that this info is available i think you can solve your issue by following this thread about Gnome 3 brightness.
https://bbs.archlinux.org/viewtopic.php?id=149316

Last edited by teateawhy (2012-10-14 10:45:40)

tancrackers · 2012-10-15 03:15:05

That solved my problem from logging in and on.
I should have been much more specific, however.
I use Gnome, but I have used other DEs. I have this problem with all of them.
Specf, KDE, xfce4, cinnamon, lxde.
I used the solution from the thread that you provided, but it only works for gnome after you logged in.
My problem persists during boot itself.
When my startup processes appear on the screen, I can actually see the screen dim to a low brightness.
This is a deeper problem than my DE.
This even happens when booting into an Arch installation disc.
Also, this happens in every Linux distro I have used on this laptop (Ubuntu, mint, fedora, opensuse).

WonderWoofy · 2012-10-15 04:12:13

I use a udev rule to set my brightness on boot.

I have a file /etc/udev/rules.d/44-backlight.conf with the following:

ACTION=="add", KERNEL=="acpi_video0", SUBSYSTEM=="backlight", SUBSYSTEMS=="pci", DRIVERS=="i915", ATTR{brightness}="2"

Now this is actually to set my backlight to just above the lowest setting, but you can make it for whatever. Keep in mind that from vendor to vendor, the numberic value of brightness is often different. For instance mine goes from 0 to 15. Also, the parameters of your rule are probably going to be different.

First figure out what controls your backlight. It is probably located in /sys/class/backlight, but I have two there. One seemingly does nothing, the other controls backlight. Mine is called acpi_video0.

To find the parameters necessary for your rule, use

$ udevadm info --attribute-walk --path=/sys/class/backlight/acpi_video0

It will give you a bunch of stuff you can use. See this page for more info:
http://www.reactivated.net/writing_udev_rules.html

Note the attribute finding commands have changed, but the rule writing info is still valid.

tancrackers · 2012-10-15 05:08:55

A part of my output confuses me:
looking at device '/devices/pci0000:00/0000:00:01.0/0000:01:00.0/backlight/acpi_video0':
    KERNEL=="acpi_video0"
    SUBSYSTEM=="backlight"
    DRIVER==""
    ATTR{type}=="firmware"
    ATTR{brightness}=="10"
    ATTR{bl_power}=="0"
    ATTR{max_brightness}=="10"
    ATTR{actual_brightness}=="10"

Why does it list no driver?

Last edited by tancrackers (2012-10-15 05:09:17)

WonderWoofy · 2012-10-15 05:15:46

Check the parent device. Mine reports the same. I think because acpi_video0 is not actually the device (card), but rather is controlled by acpi which is built into the kernel.

Indeed, acpi is compiled in

 zcat /proc/config.gz | grep -i acpi
# Power management and ACPI options
CONFIG_ACPI=y

The drive will only list a used module, so since it is not a module, I think it therefore isn't listed.

Last edited by WonderWoofy (2012-10-15 05:18:44)

Arch Linux

#1 2012-10-14 07:00:36

Backlight on HP Envy is dimmed on boot

#2 2012-10-14 10:40:43

Re: Backlight on HP Envy is dimmed on boot

#3 2012-10-15 03:15:05

Re: Backlight on HP Envy is dimmed on boot

#4 2012-10-15 04:12:13

Re: Backlight on HP Envy is dimmed on boot

#5 2012-10-15 05:08:55

Re: Backlight on HP Envy is dimmed on boot

#6 2012-10-15 05:15:46

Re: Backlight on HP Envy is dimmed on boot

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