Messages in this thread | | | Date | Tue, 3 Feb 2009 20:56:25 +0200 | From | Ville Syrjälä <> | Subject | Re: [Linux-fbdev-devel] [PATCH] atyfb: fix distorted image on PowerMacs |
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On Thu, Jan 22, 2009 at 10:12:04PM +0200, Ville Syrjälä wrote: > On Thu, Jan 22, 2009 at 08:22:48PM +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. > > AFAICS it should be the right thing to do on other systems too. I have > a good collection of mach64 pci cards and laptops so I'll try to find > some time next week to test that theory on x86.
Well, the experiment failed on the first Mobility I tried. The FIFO calculations aren't obvious from the code and there's no mention how to actually calculate them in the programming guide. So I guess special casing powermacs is the best way forward.
-- Ville Syrjälä syrjala@sci.fi http://www.sci.fi/~syrjala/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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