Re: Future features (was Re: Discussing issues)

On Wed, Apr 16, 2003 at 07:27:35PM -0400, Alan Cox wrote:
> > >    I would say that loading the driver is the domain of the operating
> > >    system, and apps/desktop only care about devices the OS has already
> > >    "found."
> 
> Not all drivers are kernel side. Its like X input devices. My pen driver
> is in XFree86 not in drivers/input, and I'd like to keep it that way 8)
> 

Right, that's an issue I have in my rough notes on this. The case I
was thinking of was printers.

When a driver is in the kernel though, from talking to you the other
day I gathered the device "exists" to most userspace apps when the
driver has been loaded. Until then we don't know whether there will be
0, 1, or N virtual devices (major/minor pairs) for a piece of
hardware. Hopefully I understood that right. ;-)

For drivers that are in userspace, we could use a similar model (the
device exists when CUPS or X has loaded it), or do something
different.
 
> USB core driver - new device 0x1111 , 0x4115, class USB storage
> USB to user space "Hey do something with this info"

So user space here is probably just a single special-purpose app that
loads usb-storage.

> User loads usb-storage
> USB storage to user space "Hey this disk has appeared"

User space here is probably all kinds of random apps that care.

Havoc