Re: LANANA: To Pending Device Number Registrants

From: Helge Hafting (helgehaf@idb.hist.no)
Date: Wed May 16 2001 - 03:29:28 EST


James Simmons wrote:
>
> > > I would use write except we use write to draw into the framebuffer. If I
> > > write to the framebuffer with that data the only thing that will happen is
> > > I will get pretty colors on my screen.
> >
> > Yes. And we also use write to send data to printer. So what? Nobody makes
> > you use the same file.
>
> Well creating a new device wouldn't make linus happen right now. I do
> agree ioctl calls are evil!!!! You only have X amount of them. With write
> you can have infinte amounts of different functions to perform on a
> device. I didn't design fbdev :-( If I did it would have been far
> different. I do plan on some day merging drm and fbdev into one interface. So
> I plan to change this behavior. I like to see this interface ioctl-less
> (is their such a word ???). You mmap to alter buffers. Mmap is much more
> flexiable than write for graphics buffers anyways. You use write to pass
> "data" to the driver.

mmap is fine for a fb, but please don't remove read/write.
I can now do a screendump with "cat /dev/fb/0 > file",
because everything is a file.
Having
/dev/fb/0/brightness
/dev/fb/0/opengl
and so on seems to be a better approach.

Helge Hafting
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This archive was generated by hypermail 2b29 : Wed May 23 2001 - 21:00:16 EST