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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 D2564C282CE for ; Mon, 11 Feb 2019 14:27:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A04F521855 for ; Mon, 11 Feb 2019 14:27:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895247; bh=tBK3CZdNZWewbfthLWZ6W3lb359IMP6SAZUEkKAm6b4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=f3SzPXg5GS2gpPgYTI/RModMESUWWEBZRc66mgPRzFIBxTQmvUdRKM0BsSAnPYm53 zt572kdH87sT0K6muj5G+01UZvlOuMT+7Lys34/dJJ/l0ww7fjrlvnZ1mJYNpMFqAB vrR5RKy5d6ecLAhpZYiHR1bsuv9pAgpshcuIC6oA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727846AbfBKO1Z (ORCPT ); Mon, 11 Feb 2019 09:27:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:33168 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729709AbfBKO1X (ORCPT ); Mon, 11 Feb 2019 09:27:23 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8806620844; Mon, 11 Feb 2019 14:27:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895242; bh=tBK3CZdNZWewbfthLWZ6W3lb359IMP6SAZUEkKAm6b4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XAGhrt1fDD4Lru0haTDzvWbeqbvpW7U4HgKGjV1fHo1Ms+ImYvyXSYoDpwcp9vYLP GyonMhwDnf7NtSFLOf5AMYQHMVFsyaRJwJ+ByaYFp+yLjMmu5O3CjEgOKA9jNHmWXJ CDm3HTNL08T6h8rv6ESmQPVCYwWL1MGzu8oAry28= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wolfram Sang , Fabrizio Castro , Guenter Roeck , Wim Van Sebroeck , Sasha Levin Subject: [PATCH 4.20 139/352] watchdog: renesas_wdt: dont set divider while watchdog is running Date: Mon, 11 Feb 2019 15:16:06 +0100 Message-Id: <20190211141855.362756843@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141846.543045703@linuxfoundation.org> References: <20190211141846.543045703@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit e990e12741877e9bfac402ca468f4007a75f6e2a ] The datasheet says we must stop the timer before changing the clock divider. This can happen when the restart handler is called while the watchdog is running. Signed-off-by: Wolfram Sang Reviewed-by: Fabrizio Castro Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin --- drivers/watchdog/renesas_wdt.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c index 0d74c3e48979..55c9eb6c6e51 100644 --- a/drivers/watchdog/renesas_wdt.c +++ b/drivers/watchdog/renesas_wdt.c @@ -74,12 +74,17 @@ static int rwdt_init_timeout(struct watchdog_device *wdev) static int rwdt_start(struct watchdog_device *wdev) { struct rwdt_priv *priv = watchdog_get_drvdata(wdev); + u8 val; pm_runtime_get_sync(wdev->parent); - rwdt_write(priv, 0, RWTCSRB); - rwdt_write(priv, priv->cks, RWTCSRA); + /* Stop the timer before we modify any register */ + val = readb_relaxed(priv->base + RWTCSRA) & ~RWTCSRA_TME; + rwdt_write(priv, val, RWTCSRA); + rwdt_init_timeout(wdev); + rwdt_write(priv, priv->cks, RWTCSRA); + rwdt_write(priv, 0, RWTCSRB); while (readb_relaxed(priv->base + RWTCSRA) & RWTCSRA_WRFLG) cpu_relax(); -- 2.19.1