Re: odd usbdevs output

From: Bernd Walter <ticso_at_cicely12.cicely.de>
Date: Mon, 6 Aug 2007 11:26:50 +0200
On Mon, Aug 06, 2007 at 03:31:20AM +0300, Giorgos Keramidas wrote:
> Hi all,
> 
> I recently acquired a USB stick which seems to work with umass but shows
> odd output in "usbdevs":
> 
> % keramida_at_kobe:/home/keramida$ sudo usbdevs -dv
> % Password:
> % [...]
> % Controller /dev/usb4:
> % addr 1: high speed, self powered, config 1, EHCI root hub(0x0000), Intel(0x0000), rev 1.00
> %   uhub4
> %  port 1 addr 2: high speed, power 80 mA, config 1, USB Mass Storage Device(0x0163), ????????y(0x1307), rev 1.00
> %    umass0
> % [...]
> 
> Does the odd `????????y' vendor name mean that the kernel prints random
> `garbage' here?  If that is so, how can I use kdb and watch this while
> it happens?

It does mean, that the device has an unprintable name.
The strings in USB are unicode and the device is free to use non ascii
character, but the kernel has to reduce it to printable ascii ones
and replaces ever other character with an '?'.
But more often than using non ascii characters broken devices uses
plain ascii with garbage in the high byte.
Anyway - it's the device sending non ascii codes.

-- 
B.Walter                http://www.bwct.de      http://www.fizon.de
bernd_at_bwct.de           info_at_bwct.de            support_at_fizon.de
Received on Mon Aug 06 2007 - 07:40:05 UTC

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