From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Date: Mon, 05 May 2014 17:09:24 +0000 Subject: Re: Clarification regarding USB Data Card (Dongle) enumeration in Linux udev Message-Id: <20140505170924.GC4850@kroah.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-hotplug@vger.kernel.org On Mon, May 05, 2014 at 09:13:08AM +0530, Suresh Kumar N. wrote: > Dear Greg, > > Data Card here refers to 3G Dongle. There is not any "standard" for these. > Yes, it is right; device enumeration depends on the device itself. > But, there must be some guideline defined regarding the same. > > As per the link (http://www.linux-usb.org/usb.devices.txt) USB device > cannot be enumerated as Network controllers, please correct me if > something has been overlooked. Not true, I have a usb network device right here. > Would all 3G Dongle devices be enumerated as "ACM USB modems"? Not at all, some show up as a custom USB to serial device, some as a network device, and others as a ACM modem. Again, look at the USB descriptors in the device, that will tell you how the device is to be communicated with. greg k-h