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-   -   why is usb device recognized? (http://www.linuxquestions.org/questions/linux-hardware-18/why-is-usb-device-recognized-247951/)

kangaman 10-27-2004 11:38 AM

why is usb device recognized?
 
Hi.

I have what may seem like a strange question! I have a USB key -- a small 128 MB SANdisk Cruzer mini. I insert the key into my machine, and the device is recognized. At least I see:

hub.c: new USB device 00:1d.7-5, assigned address 6
usb.c: USB device 6 (vend/prod 0x781/0x7103) is not claimed by any active driver.
Initializing USB Mass Storage driver...
usb.c: registered new driver usb-storage
scsi0 : SCSI emulation for USB Mass Storage devices
Vendor: Generic Model: STORAGE DEVICE Rev: 0026
Type: Direct-Access ANSI SCSI revision: 02
Attached scsi removable disk sda at scsi0, channel 0, id 0, lun 0
SCSI device sda: 256000 512-byte hdwr sectors (131 MB)
sda: Write Protect is off
sda: sda1
WARNING: USB Mass Storage data integrity not assured
USB Mass Storage device found at 6
USB Mass Storage support registered.

----

What I don't understand is *why* the USB Mass Storage driver loads.

The vendor id is: 0x781, the product id: 0x7103, the device id: 26

I'm running a 2.4.26 kernel, and if I look in lib modules/2.4.26/modules.usbmap, there are
four entries:
usb-storage 0x000f 0x0781 0x0001 0x0200 0x0200 (0x000.....)
usb-storage 0x000f 0x0781 0x0002 0x0009 0x0009 (0x000.....)
usb-storage 0x000f 0x0781 0x0100 0x0100 0x0100 (0x000.....)
usb-storage 0x000f 0x0781 0x0200 0x0000 0x9999 (0x000....)

... not one of them matches my product.

usb.handmap or usb.usermap in /etc/hotplug do not contain entries for the device.
Even usb.distmap which isn't used for the 2.4 series of kernels contains the same lines
as the ones that come with the module.

Thanks in advance!

Kangaman.


I want to understand why the USB device is recognize

SciYro 10-27-2004 12:05 PM

usb mass storage is a way for accessing files thru usb, lots of usb devices use the usb mass storage instead of some secret access method (don't let the "mass storage" part fool ya, even cameras can use usb mass storage to allow computers to get info from the device)


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