Re: 2.6.0-test1: Framebuffer problem

From: Geert Uytterhoeven (geert_at_linux-m68k.org)
Date: 07/21/03

  • Next message: David Brownell: "Re: Support sharp zaurus C-750"
    Date:	Mon, 21 Jul 2003 22:14:17 +0200 (MEST)
    To: Alan Cox <alan@lxorguk.ukuu.org.uk>
    
    

    On 19 Jul 2003, Alan Cox wrote:
    > On Sad, 2003-07-19 at 07:02, Geert Uytterhoeven wrote:
    > > No, that's not so simple, because vesafb requests the linear frame buffer,
    > > while vga16fb requests the VGA region.

    Correction:
      - vesafb uses
          o request_mem_region() on the linear frame buffer
          o request_region() on the 32 VGA registers (but the return code is
            ignored because of vgacon)
      - vga16fb doesn't use resource management (ugh)
      - vgacon uses
          o request_region() on the MDA/CGA/EGA/VGA registers

    > In standard usage mode both of them use the vga registers for palette control..

    Vesafb may use a protected mode BIOS call instead.

    An additional complexity is that not only vesafb/vga16fb may claim the VGA
    registers, but also vgacon. And it's allowed for vesafb/vga16fb to take over
    vgacon.

    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
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  • Next message: David Brownell: "Re: Support sharp zaurus C-750"

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