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 49416C11D0C for ; Thu, 20 Feb 2020 18:11:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2114F2067D for ; Thu, 20 Feb 2020 18:11:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728770AbgBTSLD (ORCPT ); Thu, 20 Feb 2020 13:11:03 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:56932 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727553AbgBTSLC (ORCPT ); Thu, 20 Feb 2020 13:11:02 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:477::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 2F3A715AC0C32; Thu, 20 Feb 2020 10:11:02 -0800 (PST) Date: Thu, 20 Feb 2020 10:11:01 -0800 (PST) Message-Id: <20200220.101101.1993510182065744262.davem@davemloft.net> To: esben@geanix.com Cc: netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, andrew@lunn.ch, michal.simek@xilinx.com, ynezz@true.cz Subject: Re: [PATCH net 2/4] net: ll_temac: Add more error handling of dma_map_single() calls From: David Miller In-Reply-To: <87v9o18xqd.fsf@geanix.com> References: <65907810dd82de3fcaad9869f328ab32800c67ea.1582108989.git.esben@geanix.com> <20200219.105954.1568022053134111448.davem@davemloft.net> <87v9o18xqd.fsf@geanix.com> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 20 Feb 2020 10:11:02 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Esben Haabendal Date: Thu, 20 Feb 2020 09:32:58 +0100 > David Miller writes: > >> From: Esben Haabendal >> Date: Wed, 19 Feb 2020 11:54:00 +0100 >> >>> @@ -863,12 +865,13 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev) >>> skb_dma_addr = dma_map_single(ndev->dev.parent, skb->data, >>> skb_headlen(skb), DMA_TO_DEVICE); >>> cur_p->len = cpu_to_be32(skb_headlen(skb)); >>> + if (WARN_ON_ONCE(dma_mapping_error(ndev->dev.parent, skb_dma_addr))) >>> + return NETDEV_TX_BUSY; >> >> The appropriate behavior in this situation is to drop the packet and return >> NETDEV_TX_OK. > > Ok, and I guess the same goes for the error handling of dma_map_single() > of one of the fragments later in same function. Yes.