RE: [Bugreport] Screen backllight issues on FirePro M5950 (HPEliteBook 8560w)

From: Deucher, Alexander
Date: Mon Nov 21 2011 - 14:45:45 EST


> -----Original Message-----
> From: Artur Flinta [mailto:aflinta@xxxxxxxxx]
> Sent: Monday, November 21, 2011 2:04 PM
> To: linux-kernel@xxxxxxxxxxxxxxx
> Cc: Deucher, Alexander; airlied@xxxxxxxxxx
> Subject: [Bugreport] Screen backllight issues on FirePro M5950 (HP EliteBook
> 8560w)
>
> Hi!
>
> I have HP Elitebook 8560w with FirePro M5950, Fedora 16, kernel 3.1.1, xorg
> ati driver 6.14.3 and issues with screen backlight - can't dim it.I can write to
> /sys/class/backlight/acpi_video0/brightness values from 0 to 20 (as stated in
> max_brightness), but it have no effect on the screen, values in brightness as
> well as in actual_brightness reflects written number.
> Before system boot, I can change brightness of the screen, and it persist in
> operating system. Value of the /sys/class/backlight/acpi_video0/brightness
> indicates maximum brightness (20) even if minimal was set before boot. It
> seems that built in kernel radeon driver does not correctly handle backlight
> on this hardware.

The driver doesn't handle the backlight at all. We leave it up to ACPI.

Alex

>
> Regards
> Artur
> --
> KaÅdy problem ma swoje rozwiÄzanie, zatem jeÅeli nie ma rozwiÄzania to nie
> ma problemu.

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