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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 44FAEC38145 for ; Wed, 7 Sep 2022 08:57:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=humRnr41wuk1Vzgb3nyJ7Y09eafvtmgBngSKi+lBSjA=; b=OilCF4Q8XXuvUQCn/cAZ6MHbPB bI1/4qowDAZBsM0Y/jfXjPKV+MlidfvD6hx2daj7ArJnEqt4PmVDhwWz/l0/crS5icKIrOkoCoJXC /fF5F+l7hRNOvdrsqlFskC1Xbq+NDH4ipDtrVrJbBtYyqZwLnx6qUyNh/0sUZTBJvZY2H2NgUnpPK ltga0J59GwhrzKk/ynGIoe7llDB09HlXKaFTjljpjc9BpvN6N1y5Yih0WD1zkbIluM/mpme2Pq5KB 5Cp+DmCSnTs2aXC+4FTvjBWSsdKIobu7gpSPxx7g6EKZ6lZK+yWm+jCPjacyLefv6HD+m5VQ22v04 VbuP3m+A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVqs8-004ZIz-GB; Wed, 07 Sep 2022 08:57:24 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oVqcc-004PSE-CT for linux-nvme@lists.infradead.org; Wed, 07 Sep 2022 08:41:27 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 8ADD267373; Wed, 7 Sep 2022 10:41:17 +0200 (CEST) Date: Wed, 7 Sep 2022 10:41:17 +0200 From: Christoph Hellwig To: Sagi Grimberg Cc: John Meneghini , Hannes Reinecke , Christoph Hellwig , Keith Busch , linux-nvme@lists.infradead.org Subject: Re: [PATCH] nvme-tcp: delay error recovery after link drop Message-ID: <20220907084117.GA29779@lst.de> References: <20220714122703.67621-1-hare@suse.de> <86f1824d-72d4-72e3-0071-4a07aeb04b7b@redhat.com> <2a5f39bd-c545-1224-12af-ce16feab4b5a@grimberg.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2a5f39bd-c545-1224-12af-ce16feab4b5a@grimberg.me> 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-20220907_014122_660698_EBF298AC X-CRM114-Status: GOOD ( 14.53 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Sep 07, 2022 at 10:57:20AM +0300, Sagi Grimberg wrote: >> I'm not sure the NVMe/TCP host stack obeys this rule. >> >> The problem is, when the host fails to follow this rule, some NVMe/TCP >> controllers are found to corrupt data during cable pull tests. > > The delay needs to come explicitly from the controller, not guessed > blindly by the host. No timeout can work properly. What we need is a proper handshake.