From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Snitzer <snitzer@redhat.com>
Subject: Re: sd: workaround invalid OPTIMAL TRANSFER LENGTH
Date: Wed, 24 Apr 2013 21:44:55 -0400
Message-ID: <20130425014455.GA28078@redhat.com>
References: <20130403202124.GB2197@redhat.com>
 <yq1bo93v230.fsf@sermon.lab.mkp.net>
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To: "Martin K. Petersen" <martin.petersen@oracle.com>
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On Wed, Apr 24 2013 at  9:19pm -0400,
Martin K. Petersen <martin.petersen@oracle.com> wrote:

> >>>>> "Mike" == Mike Snitzer <snitzer@redhat.com> writes:
> 
> Mike,
> 
> Following up on our discussion at LSF/MM last week...
> 
> Mike> Workaround disk firmware that improperly sets OPTIMAL TRANSFER
> Mike> LENGTH to 0xFFFFFFFF (aka UINT_MAX or 4294967295U) by assuming
> Mike> this _optional_ BLOCK LIMITS VPD field was not specified (0).
> 
> My only real objection is that UINT_MAX appears to be completely
> coincidental. What if the next drive specifies UINT_MAX-1 or $RANDOM?
> 
> Lacking a decent heuristic I'd rather just blacklist the offending drive
> using the skip_vpd_pages knob we already have in place.

OK, sounds fine to me, thanks.