On Thu, Dec 19, 2002 at 02:32:23AM -0800, Matthew Dillon wrote:
>     It took a hellofalong time pulling my hair out trying to figure out
>     why the Sony disk-on-key I just bought didn't work.
> 
>     First I added a Quirk entry for the standard 6-byte problem, but it
>     didn't solve the problem.
> 
>     Finally, after slogging through an insane amount of debugging (I mean,
>     it really generates a lot of debugging if you turn it all on!) I came
>     up with the following patch.  It appears that when an error occurs
>     and the umass device tries to read the sense data that it fails
>     comparing:
> 
>       sc->transfer_datalen - sc->transfer_actlen != UGETDW(sc->csw.dCSWDataResidue).
> 
>     As far as I can sc->transfer_actlen is NEVER updated.  It is always 0, so
>     I don't quite see how the calculation could ever possibly be correct
>     if DataResidue is what I think it is (a count-down of the number of 
>     unused bytes after a transfer).

I can't comment on this yet.

>     Note that my other UMASS device, a compact flash reader, has always
>     worked fine with just the Quirk entry.  I really need a USB expert to
>     tell me what is going on :-) 

The problem is that an umass bulk only umass device is allowed to stall the
comunication pipe on an invalid command.
I got the impression that the umass driver doesn't clear the pipe on
errors.

-- 
B.Walter              COSMO-Project         http://www.cosmo-project.de
[EMAIL PROTECTED]         Usergroup           [EMAIL PROTECTED]


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