From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751593AbdITFbC (ORCPT ); Wed, 20 Sep 2017 01:31:02 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:44873 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbdITFa6 (ORCPT ); Wed, 20 Sep 2017 01:30:58 -0400 X-ME-Sender: X-Sasl-enc: NodKJXea2snAQpmkMaO7EJsmdCAuUhy/D70hj61KMedz 1505885457 From: Andrew Jeffery To: linux-watchdog@vger.kernel.org Cc: Andrew Jeffery , wim@iguana.be, linux@roeck-us.net, joel@jms.id.au, linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, linux-aspeed@lists.ozlabs.org, ryan_chen@aspeedtech.com Subject: [PATCH v2 1/4] watchdog: aspeed: Retain watchdog enabled state Date: Wed, 20 Sep 2017 15:00:17 +0930 Message-Id: <20170920053020.6860-2-andrew@aj.id.au> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170920053020.6860-1-andrew@aj.id.au> References: <20170920053020.6860-1-andrew@aj.id.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org An unintended post-condition of probe() is that the watchdog is disabled. This behaviour was introduced by an unnecessary write to the control register to configure the hardware based on the devicetree. The write is unnecessary because the cached control value that is manipulated by the code parsing the devicetree is eventually written by aspeed_wdt_enable(), which is when we care how the control register should be configured. Remove the write to restore expected behaviour. Fixes: b7f0b8ad25f3 ("drivers/watchdog: ASPEED reference dev tree properties for config") Signed-off-by: Andrew Jeffery --- drivers/watchdog/aspeed_wdt.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c index 79cc766cd30f..6c6dd3f4c48d 100644 --- a/drivers/watchdog/aspeed_wdt.c +++ b/drivers/watchdog/aspeed_wdt.c @@ -243,9 +243,13 @@ static int aspeed_wdt_probe(struct platform_device *pdev) if (of_property_read_bool(np, "aspeed,external-signal")) wdt->ctrl |= WDT_CTRL_WDT_EXT; - writel(wdt->ctrl, wdt->base + WDT_CTRL); - if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE) { + /* + * The watchdog is running, but invoke aspeed_wdt_start() to + * write wdt->ctrl to WDT_CTRL to ensure the watchdog's + * configuration conforms to the driver's expectations. + * Primarily, ensure we're using the 1MHz clock source. + */ aspeed_wdt_start(&wdt->wdd); set_bit(WDOG_HW_RUNNING, &wdt->wdd.status); } -- 2.11.0