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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 3F7AFC282CF for ; Mon, 28 Jan 2019 17:00:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 07ACC2175B for ; Mon, 28 Jan 2019 17:00:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548694839; bh=56sDkTOANPa2jze6owne038gvfwm3VUHezJPck7T1xU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZkykT9k8d8INqN1BvNOPP3y99zj7A7GhTd9n2tKJINPQ/dLqa70zqQCjVsmdBpGw8 W6ZoY4V9/sZdY084DPXuybh0kkqnCz5eZoTGiaLx3x+vI50LBRPV6SZytYrlMHb63Z A4wXOhTRd/SNE5JzFP0CpmUnAnrbVPBVCUlBuzdM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387912AbfA1RAd (ORCPT ); Mon, 28 Jan 2019 12:00:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:45816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733053AbfA1QPe (ORCPT ); Mon, 28 Jan 2019 11:15:34 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C6BE72148E; Mon, 28 Jan 2019 16:15:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548692134; bh=56sDkTOANPa2jze6owne038gvfwm3VUHezJPck7T1xU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bgZg8T4YWgtAlnVXqARMzDoTqJ3pAmGWbYq1vArtDlLqw2IdZgF4bCVNKKhBg8reU f29w4+iwkDUbNhHmVLgV1cxPFLEtIQ9/54kl35nN+EvqcOtXutFXIqMcSXPrGS+2Qb VbCbUjuFK0et6zB3nDjgcFjbuWQKk6ABZcgXO5wI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wolfram Sang , Guenter Roeck , Wim Van Sebroeck , Sasha Levin , linux-watchdog@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 082/170] watchdog: renesas_wdt: don't set divider while watchdog is running Date: Mon, 28 Jan 2019 11:10:32 -0500 Message-Id: <20190128161200.55107-82-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128161200.55107-1-sashal@kernel.org> References: <20190128161200.55107-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Wolfram Sang [ 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 831ef83f6de1..c4a17d72d025 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