Accessing USB Mass Storage Device

[Bernd Walter]

On Sun, Oct 23, 2005 at 07:34:45PM -0700, Daniel Rudy wrote:
> At about the time of 10/20/2005 4:04 AM, Bernd Walter stated the following:
> > On Tue, Oct 18, 2005 at 10:38:45PM -0600, M. Warner Losh wrote:
> > 
> >>In message: <43553287.4030907 at pacbell.net>
> >>            Daniel Rudy <dr2867 at pacbell.net> writes:
> >>: 
> >>: When the umass driver is compiled into the kernel, and one inserts a USB
> >>: mass storage device, how does one access the device descriptors (serial
> >>: number) while the device is listed as a da device?  I would perfer to
> >>: have the OS do all the work of accessing the hardware.
> >>
> >>The serial number can be obtained with devifo.  However, since cam
> >>doesn't hook into the device tree, mapping da number to umass number
> >>can be tricky in the arbitrary case.
> >>
> >>devinfo -v | grep umass
> >> umass0 pnpinfo vendor=0x054c product=0x014d devclass=0x00 devsubclass=0x00 release=0x0110 sernum="0052450548137984" intclass=0x08 intsubclass= at port=0 interface=0
> > 
> > 
> > This is the USB serial number, there might even exist another one
> > at CAM device layer.
> > e.g.:
> > [108]cicely13# camcontrol inquiry -n da -u 1
> > pass1: <General Flash Disk Drive 2.05> Removable Direct Access SCSI-2 device 
> > pass1: Serial Number ST92163-2000
> > pass1: 1.000MB/s transfers 
> > [110]cicely13# devinfo -v | grep umass0
> >                 umass0 pnpinfo vendor=0x0483 product=0x1307 devclass=0x00 devsubclass=0x00 sernum="4710765066451" interface=0 intclass=0x08 intsubclass=0x06 at port=1
> > 
> 
> That was one of the first things that I tried.  It didn't work.  All I
> got was a blank line.

Neither the USB serial number nor the CAM one must exist.
And if they exist noone garanties that they make sense, in the case
above the CAM one sounds more like a chip identification than a unique
serial number.
However the devinfo umass* line must exist, at least without a serial.
To make things more confusing, an USB device may even have different
serial numbers in different languages, while it is not often used an
USB device can have strings in several languages, the serial number
is not an exception here.

-- 
B.Walter                   BWCT                http://www.bwct.de
bernd at bwct.de                                  info at bwct.de