From mboxrd@z Thu Jan 1 00:00:00 1970 From: FUJITA Tomonori Subject: RE: [PATCH 3/3] mptsas: add SMP passthrough support via bsg Date: Fri, 27 Jul 2007 02:28:12 +0900 Message-ID: <20070726022605N.tomof@acm.org> References: <20070726190913A.fujita.tomonori@lab.ntt.co.jp> <664A4EBB07F29743873A87CF62C26D708B3A65@NAMAIL4.ad.lsil.com> <20070726020657P.tomof@acm.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mo11.iij4u.or.jp ([210.138.174.79]:52825 "EHLO mo11.iij4u.or.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933365AbXGZR2t (ORCPT ); Thu, 26 Jul 2007 13:28:49 -0400 In-Reply-To: <20070726020657P.tomof@acm.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Eric.Moore@lsi.com Cc: fujita.tomonori@lab.ntt.co.jp, James.Bottomley@steeleye.com, linux-scsi@vger.kernel.org, dougg@torque.net, jens.axboe@oracle.com From: FUJITA Tomonori Subject: RE: [PATCH 3/3] mptsas: add SMP passthrough support via bsg Date: Fri, 27 Jul 2007 02:09:05 +0900 > Use-space applications can put four memory addresses in the bsg (sg > v4) interface: request, response, dout_xferp, and din_xferp. > > For scsi commands, we use: > > request -> pointer to a scsi command (cmdp in sgv3) > response -> pointer to a sense buffer (sbp in sgv3) > dout_xferp -> pointer to out data > din_xferp -> pointer to in data > > For smp request/response, we use: > > request -> not used > response -> not used > dout_xferp -> pointer to a smp request frame > din_xferp -> pointer to a smp response frame > > > So we could use response field to send vendor's unique response to > user space. > > bsg wrongly assues the response field is used for sense buffer so the > maxium length is SCSI_SENSE_BUFFERSIZE, 96 bytes. I think that it's a > bit small for mpt's unique response. But, I'll fix the length > limitation bug soon. Oops, 96 bytes is large enough for mpt's unique response. Right?