Hi Mathieu,
On Thu, Jun 9, 2016 at 2:25 PM, Mathieu Malaterre <malat@xxxxxxxxxx> wrote:
> I am trying to fix an issue with color inversion in the current offb.c
> implementation. I am using a Mac Mini G4 (PPC) with:
>
> [ 0.844144] fb0: Open Firmware frame buffer device on
> /pci@f0000000/ATY,RockHopper2Parent@10/ATY,RockHopper2_A@0
>
> reported as [*]. I have tried looking at the upstream code source, and
> it appears that my configuration falls into the 'cmap_simple'. But
> other than that I failed to understand what could be wrong (palette
> would be setup backward).
The palette code for cmap_simple writes the color components in the
order RGB, while your card seems to need BGR.
Hence either the cmap_addr/cmap_data registers are wrong, or
you have to add a cmap_inverted type that writes in the BGR order.
For both cases, you have to add a check to offb_init_palette_hacks() in
drivers/video/fbdev/offb.c.
> What are the low level tool (user-space) I can use to try to
> understand what is wrong with offb on my machine without rebuilding
> the kernel (CONFIG_FB_OF is not a module) ?
I'm afraid you can't do much from userspace.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
--
To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
