Date: Thu, 19 Dec 2002 14:12:12 +0100 From: Bernd Walter <ticso@cicely8.cicely.de> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: Bernd Walter <ticso@cicely8.cicely.de>, "Brian F. Feldman" <green@FreeBSD.ORG>, Josef Karthauser <joe@FreeBSD.ORG>, freebsd-current@FreeBSD.ORG Subject: Re: UMASS USB bug? (getting the Sony disk-on-key device working). Message-ID: <20021219131211.GA29286@cicely8.cicely.de> In-Reply-To: <200212191032.gBJAWNj0039522@apollo.backplane.com> References: <200212191032.gBJAWNj0039522@apollo.backplane.com>
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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 ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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