On Mon, Apr 28, 2014 at 02:59:16PM +0300, Mathias Nyman wrote: > > > On 04/27/2014 11:11 AM, John Freed wrote: > > I hope you don't mind me writing you directly, and if someone else can > > handle this better please let me know. > > > > I'm trying to do some backend work on libusb and I notice that the > > kernel keeps all the information on the Device Descriptors except for > > the value of the Serial Number string. > > > > (Well, almost all. Oddly, the "manufacturer" string is not included for > > hubs from Intel! I presume that's because they're really PCI devices and > > there is some black magic going on in the background to fill in the USB > > device descriptor.) > > > > I'm wondering if it would be difficult for you to establish a > > "serialnumber" value in the directory that holds the other values (like > > maxchild, etc.) from the Device Descriptor. I'm not a kernel programmer, > > which is why I'm turning to you. > > > > Hi John > > I'll add this to the linux-usb mailing list. It has people with more > knowledge about generic usb core area. > > The serial number string descriptor in a device descriptor is optional, > so it might just not be there. I checked that usb core has code for > supporting string descriptors in sysfs if they exists. If the serial number is present in the device, it will show up in sysfs in a file called "serial". Most USB devices these days don't seem to have them, especially ones that are "built into" a laptop. Hope this helps, greg k-h -- 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
