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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3CE6CC4332F for ; Tue, 29 Nov 2022 08:43:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230398AbiK2InS (ORCPT ); Tue, 29 Nov 2022 03:43:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230346AbiK2InO (ORCPT ); Tue, 29 Nov 2022 03:43:14 -0500 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9021320351 for ; Tue, 29 Nov 2022 00:43:13 -0800 (PST) Received: by verein.lst.de (Postfix, from userid 2407) id 6238D68AFE; Tue, 29 Nov 2022 09:43:10 +0100 (CET) Date: Tue, 29 Nov 2022 09:43:10 +0100 From: "hch@lst.de" To: "Rao, Lei" Cc: Chaitanya Kulkarni , "kbusch@kernel.org" , "axboe@fb.com" , "hch@lst.de" , "sagi@grimberg.me" , "linux-nvme@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] nvme: clear the prp2 field of the nvme command. Message-ID: <20221129084310.GB25609@lst.de> References: <20221129014711.91305-1-lei.rao@intel.com> <15de4902-03e7-0d2c-4b4c-45d713d0f1fd@nvidia.com> <4cee0097-4f08-1990-112f-6e39229f59ef@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4cee0097-4f08-1990-112f-6e39229f59ef@intel.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 29, 2022 at 12:50:57PM +0800, Rao, Lei wrote: > stricter checks, and if prp2 is not used but has a value, some warnings will be > printed. According to the NVMe spec, it seems to write a reserved field produces > an undefined result, so maybe clearing it is better. NVMe is a little weird about reserved fields settable by the host. I don't think your controllers warnings are correct, but given that the cost of clearing is very low I think we should clear it in Linux. Please resend a patch with the clearing in the right place as suggested in my previous mail.