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 5DC4CC433EF for ; Fri, 10 Dec 2021 02:41:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236056AbhLJCpE (ORCPT ); Thu, 9 Dec 2021 21:45:04 -0500 Received: from sin.source.kernel.org ([145.40.73.55]:49906 "EHLO sin.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230087AbhLJCpC (ORCPT ); Thu, 9 Dec 2021 21:45:02 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 00D97CE25DC; Fri, 10 Dec 2021 02:41:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8282EC004DD; Fri, 10 Dec 2021 02:41:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1639104085; bh=gs1hihtp3lcVOlDvEMy2luivUpx16A21L5U7s+OO6Is=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=TOnNKJu9sCBq0U7eH3COwg2HgIlZSIjeD0xmy5rAC7VpH70oCObZVLvAIJIDFLHva 6rtjKj80ynw8KmVwj1IzGGFlBdKf1oJWGfJUWOaq78DzWVN2zx7y29AYkJNaTpYLXO RRMnNtRjSoqcXZm5NQCa3Or29kVHe6EoXcNRrW/cNBeYt5AviF++RXwQZqsBCdL3aO x91fL/IQwRVK9sk52v1VX7lxi6GIs9zpcSvQlA0iv2r3C3EfzGwwIn5Gt0UihsmMkI JfmkX5PetfR5Au98tKMdkIf8+fn8/gryrehqx/9VoY4DdNvMu18+oVA8ifo6EFnax8 sAclA5avEAY4A== Date: Thu, 9 Dec 2021 18:41:23 -0800 From: Jakub Kicinski To: Joakim Zhang , Xiaoliang Yang Cc: "davem@davemloft.net" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "peppe.cavallaro@st.com" , "alexandre.torgue@foss.st.com" , "joabreu@synopsys.com" , Yannick Vignon , "boon.leong.ong@intel.com" , "Jose.Abreu@synopsys.com" , "mst@redhat.com" , "sonic.zhang@analog.com" , "Joao.Pinto@synopsys.com" , Mingkai Hu , Leo Li Subject: Re: [PATCH net-next] net: stmmac: bump tc when get underflow error from DMA descriptor Message-ID: <20211209184123.63117f42@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: References: <20211208100651.19369-1-xiaoliang.yang_1@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 9 Dec 2021 01:31:52 +0000 Joakim Zhang wrote: > > net: stmmac: bump tc when get underflow error from DMA descriptor > > > > In DMA threshold mode, frame underflow errors may sometimes occur > > when the TC(threshold control) value is not enough. The TC value need to be > > bumped up in this case. > > > > There is no underflow interrupt bit on DMA_CH(#i)_Status of dwmac4, so > > the DMA threshold cannot be bumped up in stmmac_dma_interrupt(). The > > i.mx8mp board observed an underflow error while running NFS boot, the > > NFS rootfs could not be mounted. > > > > The underflow error can be got from the DMA descriptor TDES3 on dwmac4. > > This patch bump up tc value once underflow error is got from TDES3. > > > > Signed-off-by: Xiaoliang Yang > > 5 queues with FIFO cut-through mode can work well after applying this patch. This never worked, correct? It's not a regression fix?