> > Here is the main reasons why I have it so only one app can open /dev/fb at
> > a time. Its called SMP. Consider two apps running at the same time both
> > with /dev/fb opened. Problem:
> >
> > 1)
> > Both apps mmap the MMIO region. Both program the accel engine at the
> > same. Hey the card locks up.
> >
> > 2)
> > DRI and fbdev MMIO region. DRI is using accel engine. Some app running
> > from a xterm mmaps MMIO region then uses accel engine. The card locks up.
> >
> > 3)
> > Someone runs fbset while the X server is using accel engine via /dev/fb
> > or DRI. Card locks up. You should only change the mode when the accel
> > engine is idle.
> >
> >
> > Now do people agree with me that /dev/fb should only be opened once.
>
> Err, ...
>
> not, there is no reason i should not be able to change mode of Xfree-fbdev
> whit fbset, not sure it will work, but still that is xfree who is broken.
No the X server should change the modes. Their is also the problem of two
apps trying to set the video mode at the same time. Broken apps shouldn't
force the kernel to be broken.
> But anyway, i don't agree with you, there is no reason that a lots of people
> can open /dev/fb in read only mode, sure if some guys want to write to it at
> the same time, it could cause problems, ...
Security :) One of the goals is to allow anyone to run a app on /dev/fb.
No more root.
"Look its a text editor, no its a OS, no its Emacs"
James Simmons (o_
fbdev/gfx developer (o_ (o_ //\
http://www.linux-fbdev.org (/)_ (/)_ V_/_
http://linuxgfx.sourceforge.net
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This archive was generated by hypermail 2b29 : Wed Mar 15 2000 - 21:00:28 EST