[lkml]   [2000]   [Mar]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [linux-fbdev] fbdev 2.4.0 cleanups
    On Thu, 16 Mar 2000, Russell King wrote:
    > James A Simmons writes:
    > > Okay lets consider this. Now some video cards use different apertures for
    > > their video memory. What I mean the framebuffer location is different for
    > > 8 bit (it's little endian) and 16 bit (big endian). Consider this.
    > > You start your X server in 8 bit mode. Now it will have write access to
    > > /dev/fb. Now you start some app which opens /dev/fb in read only mode and
    > > gets the current fix info. fix->smem_start will point to the little endian
    > > aperture right. Now your X server has properly ALT whatever function keys
    > > that do change the video mode. Since the X server has write access it can
    > > change the modes. So now you switch to 16 bit color mode which means
    > > fix->smem_start has changed to the big aperture. Your other app is still
    > > writing to where the little endian aperture was which is the wrong place.
    > Unless there has been a major change in X11, I don't think that's possible.
    > I believe that the only thing that Alt +/- can do is change resolution, not
    > colour depth.
    > IIRC, colour depth requires a restart of the server and all applications.
    > Please correct me if I'm wrong.

    Yes, X can't change color depth without restarting.

    But `some app' may be something that does support color depth changing (e.g.
    plain fbset).



    Geert Uytterhoeven -- There's lots of Linux beyond ia32 --

    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
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:57    [W:0.020 / U:39.392 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site