Johannes Erdfelt writes:
> On Tue, Apr 18, 2000, Richard Gooch <rgooch@xxxxxxxxxxxxxxx> wrote:
> > I think I've got the bigger picture (USB-wise) now, thanks. So I guess
> > the next question is how we proceed?
> >
> > Obviously, you're busy patching the USB subsystem. Are you using the
> > void *private_data method of connecting device nodes to device
> > instances? IOW, ignore major&minor numbers entirely and use the method
> > I advocate in the devfs README? Is this done, or a work in progress?
>
> Yup. We use private_data to point to a struct usb_device * or a
> struct usb_endpoint_descriptor * for instance.
Really? I just did a scan of drivers/usb/ in 2.3.99-pre6-2 and I don't
see you passing pointers to <devfs_register>. In input.c all I see is
a conventional driver with basic devfs support added.
> We have a separate set of file_operations for the different types of
> nodes we want.
I only see &input_fops being passed (there's only one call to
<devfs_register> anyway:-).
> > As far as the user-space component goes, you want to have an extension
> > to devfsd. How do you see that being maintained and distributed? Your
> > earlier patch stuck it into the devfsd source tree, but I wonder if
> > that's the way you want to do it? My guess is that the USB extension
> > will be changing a lot, as new devices are supported and you come up
> > with better ways of doing things. If so, do you really want to have to
> > go through me?
>
> I'd suppose that keeping them separate would probably the best for
> now. Things will be changing rapidly and I don't want to burden the
> rest of devfs or devfsd with USB development for now.
Yeah, makes sense to me. Is there anything you need changed in devfsd?
I'm hoping that the recent changes provide you all the hooks you need.
> > BTW: how does usbdevfs tie into all this? Can we get rid of it and
> > just use devfs instead?
>
> That was the intention. The necessary support wasn't there that we
> needed, so we created it. devfs provides a super set of
> functionality that we need so making the change is not much of a
> problem.
>
> I was busy tracking down and fixing some other bugs today so I
> didn't get much time to actually work on the coding for moving the
> rest of the core to devfs, but work will continue.
In the last email I had with Thomas Sailer, he didn't seem to think
there was much advantage to using devfs, and he felt that there were
special-purpose things needed for USB that wouldn't belong in devfs.
BTW: do you prefer to be Cc'ed or not? I have duplicate filtering, so
a second copy doesn't bother me;-)
Regards,
Richard....
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