Re: Migrating to larger numbers

Nathan Hand (nathanh@chirp.com.au)
Wed, 9 Jun 1999 06:22:41 +1000


On Tue, Jun 08, 1999 at 12:16:40PM +0200, Pavel Machek wrote:
> Hi!
>
> hpa (?) is '> >'.
>
> > > You have the completely wrong idea what a device driver is! XF86_SVGA
> > > is a device driver! gpm is a device driver (mouse driver.)
> > > magicfilter/ghostscript is a device driver (printer driver.) Neither
> > > belong in the kernel.
>
> Actually, gpm is probably going to be trashed and replaced with kernel
> approach (because in-kernel input drivers mean better sharing
> etc.). XF86_SVGA already has its fbcon counterparts (like
> creatorfb).

This is a side issue I'd like to discuss.

Kernel side abstraction of mouse drivers is painful. It encourages
user space applications that take over the entire device, and this
prevents applications from sharing a device.

The perfect example is /dev/dsp. Because the interface was "fairly
good" applications chose to open(2) it. So your desktop could make
noises, but you had to kill your desktop to play an mp3.

This has led to the current mess with your choice of ESD, OSS, and
ALSALIB as the sound API. If applications had used the theoretical
libsound.so from the start, there wouldn't be this problem.

If the kernel approach results in a "fairly good" /dev/mouse, then
I can already see applications which say "you may need to kill the
X server, and gpm, and ... etc, before using this application".

Now perhaps the mouse is special because it is used by the console
but I am concerned that a good /dev/mouse interface will result in
a repeat of the sound fiasco.

-- 
Nathan Hand - Chirp Web Design - http://www.chirp.com.au/ - $e^{i\pi}+1 = 0$
Phone: +61 2 6230 1871   Fax: +61 2 6230 4455   E-mail: nathanh@chirp.com.au

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/