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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 03104C433E0 for ; Tue, 21 Jul 2020 22:34:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D49CC2073A for ; Tue, 21 Jul 2020 22:34:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728799AbgGUWe3 (ORCPT ); Tue, 21 Jul 2020 18:34:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45500 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726555AbgGUWe3 (ORCPT ); Tue, 21 Jul 2020 18:34:29 -0400 Received: from shards.monkeyblade.net (shards.monkeyblade.net [IPv6:2620:137:e000::1:9]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F647C061794; Tue, 21 Jul 2020 15:34:29 -0700 (PDT) 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 8885D11E45900; Tue, 21 Jul 2020 15:17:43 -0700 (PDT) Date: Tue, 21 Jul 2020 15:34:27 -0700 (PDT) Message-Id: <20200721.153427.1257555808984580585.davem@davemloft.net> To: yoshihiro.shimoda.uh@renesas.com Cc: sergei.shtylyov@gmail.com, kuba@kernel.org, dirk.behme@de.bosch.com, Shashikant.Suguni@in.bosch.com, netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH v3] net: ethernet: ravb: exit if re-initialization fails in tx timeout From: David Miller In-Reply-To: <1595312592-28666-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> References: <1595312592-28666-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> X-Mailer: Mew version 6.8 on Emacs 26.3 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]); Tue, 21 Jul 2020 15:17:43 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Yoshihiro Shimoda Date: Tue, 21 Jul 2020 15:23:12 +0900 > According to the report of [1], this driver is possible to cause > the following error in ravb_tx_timeout_work(). > > ravb e6800000.ethernet ethernet: failed to switch device to config mode > > This error means that the hardware could not change the state > from "Operation" to "Configuration" while some tx and/or rx queue > are operating. After that, ravb_config() in ravb_dmac_init() will fail, > and then any descriptors will be not allocaled anymore so that NULL > pointer dereference happens after that on ravb_start_xmit(). > > To fix the issue, the ravb_tx_timeout_work() should check > the return values of ravb_stop_dma() and ravb_dmac_init(). > If ravb_stop_dma() fails, ravb_tx_timeout_work() re-enables TX and RX > and just exits. If ravb_dmac_init() fails, just exits. > > [1] > https://lore.kernel.org/linux-renesas-soc/20200518045452.2390-1-dirk.behme@de.bosch.com/ > > Reported-by: Dirk Behme > Signed-off-by: Yoshihiro Shimoda > Reviewed-by: Sergei Shtylyov Applied, thank you.