Re: [PATCH] JMicron JM20337 USB-SATA data corruption bugfix -device 152d:2338

From: Tomas Styblo
Date: Tue Jul 22 2008 - 02:12:01 EST


* Robert Hancock <hancockr@xxxxxxx> [Tue, 22 Jul 2008]:
>
> In any case, given that your code apparently fixes the corruption it seems
> that srb->result is being set to SAM_STAT_CHECK_CONDITION, but the
> DID_ERROR and SUGGEST_RETRY flags are not being set. Presumably then the
> SCSI layer looks at the sense data and says "hmm, nothing to worry about
> here" and carries on.

That's exactly what I thought was happening, after a cursory
look at the SCSI code.

>
> I think we do need something like your patch, though it should likely be
> moved inside the if (need_auto_sense) check, and I don't see a reason to
> limit to this device ID only.

Thank you. This is a very insidious bug as it doesn't manifest
itself very often, months of data corruption may pass before you
notice it.

So is there a bug in the chipset, or does the error handling code
not follow specifications?

I wonder if the company that makes the chipset should be notified
about this problem?


--
Tomas Styblo <tripie@xxxxxxxx>
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