Messages in this thread | | | Date | Tue, 14 Mar 2000 11:40:20 -0500 (EST) | From | James A Simmons <> | Subject | Re: [linux-fbdev] fbdev 2.4.0 cleanups |
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On Tue, 14 Mar 2000, Sven LUTHER wrote:
> On Tue, Mar 14, 2000 at 11:02:27AM -0500, James A Simmons wrote: > > > > > > 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. > > Too, bad, ... > > fbset has a nice interface i understand, while the Xserver offer no such > thing, appart from the limited ctr+alt+[+-] stuff.
Yeah I know. It could be better.
> > Security :) One of the goals is to allow anyone to run a app on /dev/fb. > > No more root. > > I do not understand you here, ... > > whats the problem with me wanting to know what resolution my xserver is > currently running at ?
First their is app called xdpyinfo that does this. If you need a program to know this their are Xlib function calls that do this. Look at xdpyinfo source code.
> i just do a fbset -i on it, and then i can for example set the console fbdev > mode to exatcly the same to avoid slow switching between the console and X.
Thats fine. You open /dev/fb and set the mode then close /dev/fb. Then you VT switch to another VT and start X.
"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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