From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932310AbWH1BT7 (ORCPT ); Sun, 27 Aug 2006 21:19:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932313AbWH1BT7 (ORCPT ); Sun, 27 Aug 2006 21:19:59 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:24736 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S932310AbWH1BT6 (ORCPT ); Sun, 27 Aug 2006 21:19:58 -0400 Message-ID: <44F244B7.1070408@garzik.org> Date: Sun, 27 Aug 2006 21:19:51 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.5 (X11/20060808) MIME-Version: 1.0 To: Linus Torvalds CC: Stefan Richter , Ben Collins , linux-kernel@vger.kernel.org Subject: Re: [PATCH 2.6.18-rc4 1/5] ieee1394: sbp2: workaround for write protect bit of Initio firmware References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.3 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > I don't think there really is _ever_ any reason to use the 10-byte version > if the 6-byte version is expected to work. Is there? Yes, but not really important: 10-byte allows a 16-bit allocation length (additional data section), where 6-byte only allows 8-bit. However, the mode pages the kernel requests from the device are normally <= 256 bytes. In general, your intuition is correct. use_10_for_foo is largely meant for the subclass of "SCSI" devices which often don't bother to implement the 6-byte commands, forcing the software driver to emulate 6-byte. use_10_for_foo allows the software driver to eliminate that in-kernel emulation code. Jeff