Re: [PATCH] atyfb: fix distorted image on PowerMacs

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 30 Jan 2009 14:42:50 +1100 Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:

> On Thu, 2009-01-22 at 20:22 +0200, Risto Suominen wrote:
> > Since the complete re-write in 2.6.10, some PowerMacs (At least PowerMac 5500
> > and PowerMac G3 Beige rev A) with ATI Mach64 chip have suffered from unstable
> > columns in their framebuffer image. This seems to depend on a value (4) read
> > from PLL_EXT_CNTL register, which leads to incorrect DSP config parameters to
> > be written to the chip. This patch uses a value calculated by aty_init_pll_ct
> > instead, as a starting point.
> > 
> > Signed-off-by: Risto Suominen <Risto.Suominen@gmail.com>
> > ---
> > The testing is done on kernel version 2.6.18.
> 
> This also fixes my oooold wallstreet powerbook.
> 
> Andrew, do you mind if I include that in the powerpc tree ?

Go wild.

Please don't to forget to add 'Cc: <stable@kernel.org>' to the changelog
if you consider a backport to be appropriate.