On Wed, 22 Apr 2009, Kay Sievers wrote: > On Wed, Apr 22, 2009 at 17:03, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, 21 Apr 2009, Greg KH wrote: > > Nowhere in sysfs. Â I suppose it could be added to the usb_hostN class > > directory. > > What is this device be good for? Isn't it logically the same as > /sys/bus/usb/devices/host* ? > > Looks to me, without knowing why it's there, a bit like the crazy scsi > sysfs things, which spread devices all around without putting them > into a proper hierarchy. :) I'm not sure what the /sys/class/usb_host and /sys/class/usb_endpoint directories were really meant for. Right now they seem to be filled with nothing but symbolic links. The actual usb_host directories are created under the host controller devices. For example, I've got /sys/devices/pci0000:00/0000:00:1d.7/usb_host/usb_host1 /sys/devices/pci0000:00/0000:00:1e.0/0000:01:00.2/usb_host/usb_host2 and so on... I don't know why the "usb_host" directory is in the middle; it contains nothing but the usb_hostN subdirectory. Finally, usb_hostN itself doesn't contain much of interest. For EHCI controllers, the "companion" attribute is created there. Otherwise I don't believe it contains anything useful. (It used to contain debugging files, but they have been moved to debugfs.) Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
