Messages in this thread | | | Date | Tue, 14 Mar 2000 16:50:40 +0100 | From | Sven LUTHER <> | Subject | Re: [linux-fbdev] fbdev 2.4.0 cleanups |
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On Tue, Mar 14, 2000 at 10:42:48AM -0500, James A Simmons wrote: > > On Tue, 14 Mar 2000, Sven LUTHER wrote: > > > On Mon, Mar 13, 2000 at 10:27:14AM -0500, jsimmons@ugradlib.acsu.buffalo.edu wrote: > > > > > > > There is O_NDELAY for audio devices, is not it? > > > > > > Try opening /dev/dsp. I don't think it will work. It shouldn't. I can see > > > lots of problems here. > > > > > > > BTW, it is really surprising > > > > that I cannot run 'fbset' from XF86_FBDev anymore :-( > > > > > > Doesn't X server have keys to changes modes. I know the regular XFree86 > > > servers do. I have used keys for this. If X server fb doesn't do this then > > > its broken and it should function just like other X servers. > > > > changing mode is not the only reason why one wants to run fbset, ... > > 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.
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, ...
Friendly,
Sven LUTHER
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