From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: Understanding SAS Date: Fri, 31 Jul 2009 09:26:45 -0500 Message-ID: <1249050405.3922.11.camel@mulgrave.site> References: Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:36503 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751239AbZGaO0t (ORCPT ); Fri, 31 Jul 2009 10:26:49 -0400 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Madhukar G Cc: linux-scsi@vger.kernel.org On Fri, 2009-07-31 at 17:26 +0530, Madhukar G wrote: > I'm understanding SAS architecture for adaptec controller. I'm using > the source adp94xx for the same. I was able to understand all the > infomation unit flow but i'm stuck with one problem. I was not able to > trace when task management IU shall be invoked. > Do i need any special app to test task management IU? > Is SCSI layer responsible for invoking task management IU? I don't understand what you mean by IU: SAS tends to think in terms of frames (at the transport layer). Information Units as used by the SAS protocol means specific SSP frames. Task Management in SAS has to include SMP, STP and SATA as well. However, SAM task management functions all map to the callbacks in struct sas_domain_function_template which are called by libsas. These callbacks are also used for all other frame error handling. James