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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 072C4C4161F for ; Mon, 15 Mar 2021 14:06:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D3D9A64F34 for ; Mon, 15 Mar 2021 14:06:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234451AbhCOODX (ORCPT ); Mon, 15 Mar 2021 10:03:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:34534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231382AbhCON5J (ORCPT ); Mon, 15 Mar 2021 09:57:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 53E5764EFD; Mon, 15 Mar 2021 13:57:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816628; bh=/ARiGRTysZEO0zch14sIudIpLeSsRLsa8TZ0ZFfxbQc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NmoQkCSMlfYCec+n8+h0wN9bI3/YaS+AtlxUaOHLMMus2mRYsqhTBEPjPDBDJmDDe E5Iy2tWf5FmYxzbD8ARtHFM/LutuHnzoSAkZgtoR9s3KqwHHCMkY84vo/YoyMcqole zbJ6iv3k5TI4J9ORMDqAOcNj0gPMU4znOwTY00Nw= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Kleine-Budde , Torin Cooper-Bennun Subject: [PATCH 5.4 013/168] can: tcan4x5x: tcan4x5x_init(): fix initialization - clear MRAM before entering Normal Mode Date: Mon, 15 Mar 2021 14:54:05 +0100 Message-Id: <20210315135550.775526741@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135550.333963635@linuxfoundation.org> References: <20210315135550.333963635@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg Kroah-Hartman From: Torin Cooper-Bennun commit 2712625200ed69c642b9abc3a403830c4643364c upstream. This patch prevents a potentially destructive race condition. The device is fully operational on the bus after entering Normal Mode, so zeroing the MRAM after entering this mode may lead to loss of information, e.g. new received messages. This patch fixes the problem by first initializing the MRAM, then bringing the device into Normale Mode. Fixes: 5443c226ba91 ("can: tcan4x5x: Add tcan4x5x driver to the kernel") Link: https://lore.kernel.org/r/20210226163440.313628-1-torin@maxiluxsystems.com Suggested-by: Marc Kleine-Budde Signed-off-by: Torin Cooper-Bennun Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/m_can/tcan4x5x.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/net/can/m_can/tcan4x5x.c +++ b/drivers/net/can/m_can/tcan4x5x.c @@ -325,14 +325,14 @@ static int tcan4x5x_init(struct m_can_cl if (ret) return ret; + /* Zero out the MCAN buffers */ + m_can_init_ram(cdev); + ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG, TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL); if (ret) return ret; - /* Zero out the MCAN buffers */ - m_can_init_ram(cdev); - return ret; }