lkml.org 
[lkml]   [2002]   [Dec]   [23]   [last100]   RSS Feed
Views: [more markup]   [less markup]   [headers]   [forward]  
 
Messages in this thread
/
DateMon, 23 Dec 2002 10:07:35 +0100 (MET)
FromGeert Uytterhoeven <>
SubjectRe: [Linux-fbdev-devel] [PATCH] fix endian problem in color_imageblit
On Sat, 21 Dec 2002, Russell King wrote:
> On Sat, Dec 21, 2002 at 11:45:44AM +0800, Antonino Daplas wrote:
> > The pseudopalette will only matter for truecolor and directcolor as the
> > rest of the visuals bypasses the pseudopalette.  Typecasting to
> > "unsigned long" rather than "u32" is also safer (even for bpp16) since
> > in 64-bit machines, the drawing functions use fb_writeq instead of
> > fb_writel.
> 
> Erm, what does the size of the drawing functions have to do with the
> size of the pseudo palette.  The pseudo palette is only there to encode
> the pixel values for the 16 console colours.

Indeed.

> This means that a 64-bit pseudo palette would only be useful if you have
> a graphics card that supports > 32bpp, otherwise a 32-bit pseudo palette
> is perfectly adequate, even if you are using fb_writeq.

Yep. Cards with bpp > 32 are rumoured to exist, but there is no fbdev support
for them right now.
> (note that fbcon doesn't support > 32bpp, so we will only ever look at
> the first 32 bits, and having it be 64-bit would just be a needless
> waste of space imho.)

And this can be fixed, once we have some fbdev driver that uses bpp > 32.
Note that the size of the entries in the pseudo palette used to depend on the
mode, i.e. u16 for bpp = 16, u32 for bpp = 24 or 32.

Gr{oetje,eeting}s,
						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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-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/

\
 
 \ /
  Last update: 2005-03-22 11:31    [W:0.082 / U:0.140 seconds]
©2003-2008 Jasper Spaans