From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Smart Subject: Re: [RFC] pass through support in fc transport: via bsg (block SG) Date: Fri, 22 Aug 2008 17:53:11 -0400 Message-ID: <48AF3547.4040703@emulex.com> References: <1283B1A7-A1A2-465A-A9E4-07A778BC3FE8@qlogic.com> <423FD491-FCA2-4CBF-8411-B08E90243236@qlogic.com> <7773BCE2-99A3-467D-B7AF-C182F2773A9C@qlogic.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from emulex.emulex.com ([138.239.112.1]:39122 "EHLO emulex.emulex.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757028AbYHVVxf (ORCPT ); Fri, 22 Aug 2008 17:53:35 -0400 In-Reply-To: <7773BCE2-99A3-467D-B7AF-C182F2773A9C@qlogic.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Seokmann Ju Cc: Robert W Love , "linux-scsi@vger.kernel.org" , Andrew Vasquez , Boaz Harrosh , Mike Christie Nope - not forgotten, just a lot of different things to get to. I don't know of anything in the header that needs to be specified. Everything is either fixed because it is an ELS/CT request, or what needs to be specified (usually S_ID/D_ID) comes from the object the bsg reference is to. CS_CTL is the only one that is a maybe - but that's a whole different story, and we should just ignore it for now. So I'm against a header. Additionally, we have to be careful about what kind of interface we believe the LLD's support. If they expected a raw frame transmit, I don't know how many support that, especially as adapters very much control XID's, etc. Create Exchange, w/ Send/Receive, sequence is prefered, but even that might be too low. At best, there is explicit els or ct assist interfaces - which means the LLD/adapter is likely handling all the header and segmentation, and the interface is just passing payload buffers. So in general it's a request, w/ xmt payload, buffer for response, and a completion status (which I would assume is more than just an int and a couple of #defines - we have to cover the F_RJT/P_RJT/ABORT cases..) -- james s Seokmann Ju wrote: > I just want to re-stroke this thread to make sure it is not skipped. > > One question came to me while testing qla2xxx module with the changes. > When the application issues ELS/CT packet, should the packet include > the FC frame header? > And if the answer is 'yes', should the driver also include the FC > frame header when it returns response to the application (just like > any other frame exchanges in between two ports on the FC)? > The FC frame header has type field that identifies what type of the > payload (ELS / CT / etc.) the frame contains and the type field is > being checked by the FC transport layer before it calls LLDD's handler. > > Thank you, > Seokmann