I sense a certain theme here... :-) On Sun, 22 Apr 2007, Greg KH wrote:
> > Something I've meant to ask for a while... What about things that apply > > to an entire interface or device, as opposed to a single endpoint? > > > > In addition to sending or cancelling URBs, usbfs allows users to: > > > > Issue a USB port reset to the device; > > > > Find out the name of the driver bound to an interface; > > Use sysfs A little tricky, since it involves parsing the last component of a pathname stored in a symlink, but doable. > > Unbind a kernel driver from an interface; > > Use sysfs > > > Find out the device's address and speed (although it doesn't > > distinguish between full and high); > > Use sysfs > > > Change the altsetting for an interface; > > Use sysfs Actually this cannot be done using sysfs. The bAlternateSetting attribute is read-only. As it should be, since the altsetting is supposed to be determined by the driver owning the interface. The case in question arises when a userspace driver owns the interface via usbfs. The driver then needs a way to select an altsetting. > > Change the device configuration; > > Use sysfs > > > Claim (bind usbfs to) an interface; > > Use sysfs Again, it can't be done. You can use sysfs to bind a kernel driver to an interface, but you can't use it to bind a userspace program the way usbfs allows. > > Release (unbind usbfs from) an interface. > > Use sysfs Likewise here. > Let's not have a lot of duplication if we can help it :) I agree. Most of these things can indeed be done through sysfs. The hardest aspect is matching up pathnames in usbfs with the corresponding pathnames in sysfs. Going from a usbfs name to a sysfs path can be accomplished by looking in /sys/class/usb_device. The other direction is a little harder. We have a "devnum" attribute but not a "busnum" attribute. Should I add one? Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
