Messages in this thread | | | Date | Fri, 17 Mar 2000 07:58:06 +0100 (MET) | From | Geert Uytterhoeven <> | Subject | Re: [linux-fbdev] fbdev 2.4.0 cleanups |
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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).
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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