usb/137189: [usb][patch] create and use sysctl nodes for HID report descriptors

[Hans Petter Selasky]

On Thursday 30 July 2009 22:38:12 Eygene Ryabinkin wrote:
> Hans Petter, good day.
>
> Tue, Jul 28, 2009 at 07:40:27PM +0400, Eygene Ryabinkin wrote:
> > HPS wrote:
> > > > Why do you dislike the sysctl approach? It is simple and reliable.
> > >
> > > It's duplicating access to data. There is not that much wrong about
> > > it, except it will not work if the device is of another kind. I.E. you
> > > would have to patch the HID sysctl node into every driver accessing
> > > HID descriptors?
> >
> > Just now -- yes, I'll need it.  But probably I can move this
> > functionality into the USB bus level -- it will automatically create
> > this sysctl node for all HID children and will dispose it on the detach.
> > usb_probe_and_attach() is a candidate for such functionality.  Will it
> > be bad?
>
> OK, attached is the reworked version of the sysctl patch: it now creates
> the needed nodes automatically (though they still can be created by
> explicit call from the driver, as in uhid(4)).  As a bonus, kernel got the
> ability to install per-USB class post-attach and pre-detach handlers, so
> we can do some class-specific things for every driver.  What do you think
> of it?

Hi,

I think it's too much code to doo too little, and adds extra complexity, and 
that doing this via libusb would be much more generic.

--HPS