From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751571AbdCCITu (ORCPT ); Fri, 3 Mar 2017 03:19:50 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:56427 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751323AbdCCITs (ORCPT ); Fri, 3 Mar 2017 03:19:48 -0500 From: Alexandre Belloni To: Guenter Roeck Cc: Wim Van Sebroeck , Nicolas Ferre , Wenyou.Yang@microchip.com, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Alexandre Belloni Subject: [PATCH 4/4] watchdog: sama5d4: Add comment explaining what happens on resume Date: Thu, 2 Mar 2017 18:31:14 +0100 Message-Id: <20170302173114.28508-5-alexandre.belloni@free-electrons.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170302173114.28508-1-alexandre.belloni@free-electrons.com> References: <20170302173114.28508-1-alexandre.belloni@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Because suspending to RAM may lose the register values, they are restored on resume. This is currently done unconditionally because there is currently no way to know (from the driver) whether they have really been lost or are still valid. Writing MR also pings the watchdog and this may not be what is expected so add a comment explaining why it happens. Signed-off-by: Alexandre Belloni --- drivers/watchdog/sama5d4_wdt.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/watchdog/sama5d4_wdt.c b/drivers/watchdog/sama5d4_wdt.c index d710014f3b7d..0ae947c3d7bc 100644 --- a/drivers/watchdog/sama5d4_wdt.c +++ b/drivers/watchdog/sama5d4_wdt.c @@ -300,6 +300,11 @@ static int sama5d4_wdt_resume(struct device *dev) { struct sama5d4_wdt *wdt = dev_get_drvdata(dev); + /* + * FIXME: writing MR also pings the watchdog which may not be desired. + * This should only be done when the registers are lost on suspend but + * there is no way to get this information right now. + */ sama5d4_wdt_init(wdt); return 0; -- 2.11.0