From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5A5BC432C0 for ; Tue, 19 Nov 2019 23:13:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C56222245B for ; Tue, 19 Nov 2019 23:13:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727405AbfKSXNE (ORCPT ); Tue, 19 Nov 2019 18:13:04 -0500 Received: from kvm5.telegraphics.com.au ([98.124.60.144]:34902 "EHLO kvm5.telegraphics.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726539AbfKSXNE (ORCPT ); Tue, 19 Nov 2019 18:13:04 -0500 Received: from localhost (localhost.localdomain [127.0.0.1]) by kvm5.telegraphics.com.au (Postfix) with ESMTP id 4A77D285D9; Tue, 19 Nov 2019 18:12:58 -0500 (EST) Date: Wed, 20 Nov 2019 10:12:21 +1100 (AEDT) From: Finn Thain To: Kars de Jong cc: "James E.J. Bottomley" , "Martin K. Petersen" , Michael Schmitz , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] esp_scsi: Clear Transfer Count registers before PIO transfers In-Reply-To: Message-ID: References: <2bbb6359d542f5882be67c415ecc25ad2d9eeb5e.1573875417.git.fthain@telegraphics.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 19 Nov 2019, I wrote: > > But this is a theoretical problem so far. You may need to use sg_utils > to generate a SCSI command like that. > > (For a DMA controller subject to, say, 24-bit boundaries, there are > additional ways to end up with short transfers.) > On reflection these probably can't happen in practice. I was being over-cautious. So I'll leave this patch out-of-tree until there's a need for it (i.e. some driver that uses both DMA and PIO in data phases). --