Re: [linux-usb-devel] [PATCH] USB: Only enable autosuspend by default on certain device classes

[Greg KH <gregkh@suse.de>]

On Fri, Aug 03, 2007 at 09:29:16AM -0700, David Brownell wrote:
> On Friday 03 August 2007, Matthew Garrett wrote:
> > > Speaking of which, what's this /dev/bus/usb/* crap on Ubuntu?
> > > I had to undo all that on my Feisty system before any normal
> > > /proc/bus/usb stuff would work again.
> > 
> > "Usbfs files can't handle Access Control Lists (ACL), which are the 
> > default way to grant access to USB devices for untrusted users of a 
> > desktop system. The usbfs functionality is replaced by real device-nodes 
> > managed by udev. These nodes live in /dev/bus/usb and are used by 
> > libusb."
> > 
> > (From Kconfig)
> 
> That's shortly after the explanation that the relevant Kconfig
> option is for  ** /proc/bus/usb ** files ... note that despite the
> strangeness in that text (usbfs still hasn't been "replaced", so
> that should say "will eventually be replaced" not "is replaced"),
> it's clear that /proc/bus/usb/ and /dev/bus/usb/ are two different
> things.  And thus:  that Ubuntu's /dev/bus/usb/ setup is flakey.

Hm, if you look at SuSE and Fedora, they too are putting usbfs in
/dev/bus/usb/ now, not mounting the filesystem, but using the device
nodes for access due to ACLs for local users.

libusb works just fine with this, and I think that all other programs
that directly access the old /proc/bus/usb mount are fixed up, with the
exception of usbview (but I do have patches floating around for that to
solve it.)

thanks,

greg k-h