Re: [BUG] Strange interaction between X and /dev/fb0 + /dev/fb1

["Antonino A. Daplas" <adaplas@gmail.com>]

Knut Petersen wrote:
> Hi everybody,
> 
>  1: the system boots with video=vesafb:ypan
>  2: cyblafb is loaded by the boot.local script
>  3: con2vt /dev/fb1 /dev/tty1
>  4: runlevel 3 (no X) is used
> 
> As cyblafb detects the video mode used by vesafb, everything works
> fine. If I switch to tty1, the accelerated cyblafb driver is used, all 
> other
> ttys use the slow  vesafb code.
> I can unload cyblafb after a con2ct /dev/fb0 /dev/tty1, load it again, 
> switch
> between ttys, everything without a problem.
> 
> Now I switch to runlevel 5.
> 
>  1: Switching from X to any tty, no matter if it is managed
>     by vesafb or cyblafb,does work without problems.

X restores, at least partially, the state of the card, then set_par
is called which fully restores the state of cyblafb.

>  2: Switching from any tty to X works without a problem.

X usually does a good job of restoring it's own state.

>  3: Switching from X to any tty except tty1 (managed by cyblafb)
>     and then between any ttys works without problems.

Vesa state is usually restored fully by X, so even if vesafb has
no set_par, vesafb comes back working.

> 
>  4: Switching from X to tty1 and then to any other tty does _not_
>     work. The cursor stops blinking, otherwise nothing changes
>     on the monitor. Blindly entered commands produce no visible
>     output, but they are executed.

I don't know why.  But try switching from tty1->X->tty1->!tty1 and
!tty1->X->tty1->!tty1. Do you still get the same behavior?
 
Tony


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