[Gta04-owner] Linux 3.2-rc2 on GTA04

Johannes Schauer j.schauer at email.de
Thu Nov 24 23:04:13 CET 2011


On Fri, Nov 25, 2011 at 08:29:48AM +1100, NeilBrown wrote:
> On Thu, 24 Nov 2011 21:57:04 +0100 "Dr. H. Nikolaus Schaller"
> <hns at goldelico.com> wrote:
> > > The gpio line can be controlled from /sys/class/gpio/gpio57
> > > 
> > > cd /sys/class/gpio/gpio57
> > > echo 1 > value
> > > 
> > > however I suspect you will find that '1' is already the value.

no, the value I find there is 0

> > > I didn't change any of this code from the code David had, except
> > > that I replaced the base kernel:-) So presumably there is some
> > > change in common code that is messing things up.

but the backlight works fine before xorg comes up - i can see the

> > Are you sure that the backlight really turns off? Or does the
> > framebuffer turn completely black? In that case you see some light
> > glowing. If you remove the battery, there should be a noticeable
> > change.
> The original report said that shining a bright torch the display made the
> image just visible, so it wasn't blank, just no backlight.
> Very strange.

yes, it is the backlight. here is a photo of the display with my
flashlight shining on it:


you can faintly see the e17 language selection menu with the USA flag in
the center of the photo.

after doing:

	echo 1 > /sys/class/gpio/gpio57/value


	echo 1 > /sys/devices/virtual/gpio/gpio57/value

the display will turn on.

after some time e17 will turn off the display. this works properly and
the values in */gpio/gpio57/value will correctly change to 0 but when
tapping the display (touchscreen works) the values will still remain
zero and backlight will not come back until one does echo 1 > ...

the exact same image with xorg7.6+e17 is working fine with davids 3.1

cheers josch

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