[sane-devel] How to read the usb-snoopy log?

Jaeger, Gerhard gerhard@gjaeger.de
Mon, 30 Sep 2002 20:11:44 +0200

Hi Frank,

thanks for the response,  I might be able to figure out whats
happening now. The chip inside is reported as
GLUSB97 SC08-D047 or as
GENIUS 04-43-006B 9935

Maybe custom ASICs...

I only have some logs, where I'm able to identify some well known
byte sequences. I do not own such a scanner, but I wrote the driver
for the parallelport devices whose ASIC is now behind the bridge
so the idea was simply to replace the I/O layer by USB I/O functions...


On Sunday, 29. September 2002 20:12, Frank Zago wrote:
> Hi list member Gerhard,
> If you read the usb logs, you should be able to detect the pp commands.
> What might be confusing is that a lot of usb packet may be sent/received
> just for one command. The bridge chip may also need some inititialisation.
> You can look into umax-usb.c. This file is used to send scsi commands
> through usb. The function sanei_umaxusb_cmd() is where all the work is
> done. Basically there a dialogue like
> host: i'm going to send a cdb. tell me whenever you're ready.
> scanner: i'm ready
> host: here is the cdb. tell me whenever you've received it.
> scanner: i got it.
> host: i also have to sending some data. tell me when you got them.
> scanner: i got them
> host: tell me when the command is completed
> scanner: it is now
> and so on.
> So for just a single CDB, the host has sent about 30 messages.
> Does your scanner uses only bulk messages or both bulk and control
> messages? Control messages can be used to prepare a command and bulk
> message can be used to send/receive the real data. You should see that in
> the logs.
> You should post your logs somewhere. It is possible that your scanner uses
> an already know bridge, and someone could identify it.