G3 iBook LCD brightness in X under kernel 2.4.25 and 2.6.8

Frank Murphy murphyf+xfree86 at f-m.fm
Mon Nov 29 07:14:46 EST 2004


On Sunday 28 November 2004 2:58, Benjamin Herrenschmidt wrote:
> >
> > So I've tried this using the stock Debian 2.6.8 and 2.6.9 PPC kernels
> > with the same results.
> >
> > $ grep ATY /boot/config-2.6.9-powerpc
> > CONFIG_FB_ATY128=y
> > CONFIG_FB_ATY=y
> > CONFIG_FB_ATY_CT=y
> > CONFIG_FB_ATY_GX=y
> > # CONFIG_FB_ATY_XL_INIT is not set
> >
> > It seems that the atyfb module is compiled in. Is there another way to
> > check?
>
> Check the bits in CONFIG_PMAC_BACKLIGHT in atyfb (like, add some
> printk's to see if they are reached etc..)

So I added a couple of printk()s like you asked. I added one to 
aty128fb_blank() in aty128fb.c:2037 and two to aty_init() in 
atyfb_base.c:1793 and 1802 (inside the 'if (M64_HAS(MOBIL_BUS))'). The one I 
added to aty128fb didn't print (as expected), but both of them from 
atyfb_base.c printed. So it seems that CONFIG_PMAC_BACKLIGHT is properly 
defined. Anything you'd specifically like me to try?

I find it interesting that in the console the dimming works. I thought that on 
PPC the console used the framebuffer. Another notable thing is that while in 
X, the dimming doesn't work, but when I switch to one of the VTs, the screen 
brightness is adjusted to what it should have been in X.

Thanks for your help on this,

Frank



More information about the Linuxppc-dev mailing list