From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH] megaraid_sas: Enable shared tag map Date: Thu, 02 Oct 2014 11:50:42 +0200 Message-ID: <542D1FF2.1010307@suse.de> References: <1411991272-129962-1-git-send-email-hare@suse.de> <542C4D33.2030401@hp.com> <20141001211003.GA24820@infradead.org> <542CF5E8.3030601@suse.de> <20141002091916.GA13227@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:58521 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751176AbaJBJuo (ORCPT ); Thu, 2 Oct 2014 05:50:44 -0400 In-Reply-To: <20141002091916.GA13227@infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: Webb Scales , James Bottomley , linux-scsi@vger.kernel.org On 10/02/2014 11:19 AM, Christoph Hellwig wrote: > On Thu, Oct 02, 2014 at 08:51:20AM +0200, Hannes Reinecke wrote: >> >> I'm afraid it's not _that_ easy. >> SCSI-II tagged queueing has some specific tag values: >> >> #define SIMPLE_QUEUE_TAG 0x20 >> #define HEAD_OF_QUEUE_TAG 0x21 >> #define ORDERED_QUEUE_TAG 0x22 >=20 > These are not tag values. These are message codes set in the first b= yte > of the Queue tag message, the second byte is the actual tag. >=20 >> The recommendation here is to use 'scmd->request->tag' whenever >> you want to get to the tag number, and 'scmd->tag' if you have to >> play around with SCSI-II TCQ. >> But if not I would strongly advise to leave 'scmd->tag' alone. >=20 > Or kill off scmd->tag.. Let's see how feasible that is. >=20 I'm about to. (See my last two patches). There are now two instances left: NCR5380 (and derived LLDDs) and fnic. =46or some weird reasons fnic decided to duplicate blk-tag functionality. Looking into it. And NCR5380 tag support can be safely ignored, it never worked anyway. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html