[Gta04-owner] Linux 3.2-rc2 on GTA04

Dr. H. Nikolaus Schaller hns at goldelico.com
Thu Nov 24 21:27:49 CET 2011


Am 24.11.2011 um 21:16 schrieb Johannes Schauer:

> Hi,
> 
> On Wed, Nov 23, 2011 at 06:42:38AM +1100, NeilBrown wrote:
>> I don't even have a display plugged in - just the bare board with a
>> paperclip to hold the battery in place, and the serial and USB cables
>> plugged in.
>> 
>> As far as I can see, the backlight control code I have is exactly what is in
>> the 3.1 'master' branch of the goldelico git tree.

>> 
>> It contains:
>> 
>> 	gpio_set_value(57, 0); //shutdown backlight first
>> 
>> in gta04_init() in arch/arm/mach-omap2/board-omap3gta04.c
>> 
>> The hw-validation kernel doesn't have that line.  You could try removing it
>> and see what happens.
>> It was added by commit 8d109e588b840c288ea1ad4d8f166080510be55a with minimal
>> explanation.
> 
> There is no difference after removing that line.
> 
> Additionally, the backlight only turns off once xorg is starting. Before
> the backlight is on and shows the penguin.

Could it be that xorg has some parameter to blank the screen
and hide the pointer instead of showing the background dot matrix?

> 
> Is there something in /sys that I can use to control the backlight?

Yes:

http://projects.goldelico.com/p/gta04-kernel/page/Devices/#wikititle_4

(unless gpio 57 is not exported in your kernel's boardfile).

BR,
Nikolaus




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