From patchwork Mon Mar 15 13:54:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 401571 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=ham 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 C6B19C2BBD4 for ; Mon, 15 Mar 2021 13:58:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF6C164F41 for ; Mon, 15 Mar 2021 13:58:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232076AbhCON5n (ORCPT ); Mon, 15 Mar 2021 09:57:43 -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 Precedence: bulk List-ID: X-Mailing-List: stable@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; }