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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A9510C433DB for ; Wed, 10 Feb 2021 13:16:10 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5C87F64DEE for ; Wed, 10 Feb 2021 13:16:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C87F64DEE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7IDc/wiJK9ToUryoiv00SnZ+iTCAY3GypQXHDqr7uTk=; b=QcGNSkH4HrRWRigO3ob8Hk4nO VZxCeszw8UX86468kHqHzMLjYhANmP/Gn+HLQzZMBhzgT9r2Y3fDQZ0/ZRunvg9IHpHtJoRkbOEL9 W1/isIzXfmWkRiV3KMIkWrMViZcf80Dr5sriaUyJlmjB540oxZOjDgJ+N2Uj5kjev5+k0UceHhfjl Li6vo4D8kxgW6Oaanq0d67QZ7ya1J3ghrIBbQiZFqfl5hEAVqXrP9M5buIcJz2Zk663tsOl2hGLJC LK0D5kg3TLTnJC2uxO05CSofJ8Mgzk8ErmqLsgrXOWLXgjrOxBwA0mvV9D3wuPN+Izn1L04FYMujS +MU79vlaQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9pLf-0007zZ-VQ; Wed, 10 Feb 2021 13:16:04 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9pLb-0007xf-Kt for linux-nvme@lists.infradead.org; Wed, 10 Feb 2021 13:16:01 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6CE4A6736F; Wed, 10 Feb 2021 14:15:57 +0100 (CET) Date: Wed, 10 Feb 2021 14:15:57 +0100 From: Christoph Hellwig To: Gopal Tiwari Subject: Re: [PATCH] nvme-pci: prevent SK Hynix PE8000 from using Write Zeroes command Message-ID: <20210210131557.GB29904@lst.de> References: <20210209045902.72345-1-gtiwari@redhat.com> <211078952.30654328.1612955843198.JavaMail.zimbra@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <211078952.30654328.1612955843198.JavaMail.zimbra@redhat.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210210_081559_928677_1395E2FF X-CRM114-Status: UNSURE ( 7.42 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Christoph Hellwig , kbusch@kernel.org, hch@lst.de, linux-nvme@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org MDTS vs Write Zeroes is a common misconception. We had that discussion in the NVMe working group, and while the text should pretty clear that MDTS only applies to data transfers many implementators did not understand that, which is why we added the clarification you quoted. Also the next NVMe spec will allow devices to advertise an explicit Write Zeroes limit, take a look at TP4040 from the "NVM Express 1.4 Ratified TPs" at https://nvmexpress.org/developers/nvme-specification/. So I think limiting to MDTS unless the new WZSL is set might be a fail safe option, even if it is more pessimistic than what the spec says. I'd also love to retest most Write Zeroes quirks with that in place. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme