From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762536AbZDBJcD (ORCPT ); Thu, 2 Apr 2009 05:32:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755881AbZDBJbu (ORCPT ); Thu, 2 Apr 2009 05:31:50 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:43418 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751545AbZDBJbt (ORCPT ); Thu, 2 Apr 2009 05:31:49 -0400 Message-ID: <49D48600.2070109@garzik.org> Date: Thu, 02 Apr 2009 05:31:44 -0400 From: Jeff Garzik User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Linux IDE mailing list CC: Jens Axboe , LKML Subject: IDE, packet commands and REQ_TYPE_SENSE? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.4 (----) X-Spam-Report: SpamAssassin version 3.2.5 on srv5.dvmed.net summary: Content analysis details: (-4.4 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Looking at REQ_TYPE_*, I see that REQ_TYPE_SENSE is only used once in an assignment, and appears to never be tested anywhere. Furthermore, the use of REQ_TYPE_SENSE immediately follows a previous assignment rq->cmd_type assignment: cdrom_queue_request_sense(): [...] /* stuff the sense request in front of our current request */ blk_rq_init(NULL, rq); rq->cmd_type = REQ_TYPE_ATA_PC; rq->rq_disk = info->disk; rq->data = sense; rq->cmd[0] = GPCMD_REQUEST_SENSE; rq->cmd[4] = 18; rq->data_len = 18; rq->cmd_type = REQ_TYPE_SENSE; rq->cmd_flags |= REQ_PREEMPT; [...] First, the code assigns REQ_TYPE_ATA_PC, then without any intervening tests or branches, it assigns REQ_TYPE_SENSE. So, some questions... Is REQ_TYPE_ATA_PC sufficient (i.e. the first assignment)? Can we get rid of REQ_TYPE_SENSE? What are the differences between REQ_TYPE_ATA_PC and REQ_TYPE_BLOCK_PC? Would it be possible to eliminate REQ_TYPE_ATA_PC after some work, as well? Jeff