From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752436AbbDBBVw (ORCPT ); Wed, 1 Apr 2015 21:21:52 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:34319 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751695AbbDBBVv (ORCPT ); Wed, 1 Apr 2015 21:21:51 -0400 Message-ID: <551C99A4.40608@roeck-us.net> Date: Wed, 01 Apr 2015 18:21:40 -0700 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: "Rafael J. Wysocki" , linux-watchdog@vger.kernel.org CC: Linux Kernel Mailing List , Linux PM list , Wim Van Sebroeck , Aubrey Li , Borun Fu Subject: Re: [PATCH] PM / watchdog: iTCO: stop watchdog during system suspend References: <2017660.nPaHVT8bW3@vostro.rjw.lan> In-Reply-To: <2017660.nPaHVT8bW3@vostro.rjw.lan> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020201.551C99AE.008A,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.001 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: C_4847, X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 5 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/01/2015 05:31 PM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > If the target sleep state of the system is not an ACPI sleep state > (S1, S2 or S3), the TCO watchdog needs to be stopped during system > suspend, because it may not be possible to ping it any more after > timekeeping has been suspended (suspend-to-idle does that for > one example). > > For this reason, provide ->suspend_noirq and ->resume_noirq > callbacks for the iTCO watchdog driver and use them to stop > and restart the watchdog during system suspend and resume, > respectively, if the system is not going to enter an ACPI > sleep state (in which case the watchdog will be stopped > by the platform firmware before the state is entered). > > Reported-by: Borun Fu > Signed-off-by: Rafael J. Wysocki > --- > drivers/watchdog/iTCO_wdt.c | 51 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 51 insertions(+) > > Index: linux-pm/drivers/watchdog/iTCO_wdt.c > =================================================================== > --- linux-pm.orig/drivers/watchdog/iTCO_wdt.c > +++ linux-pm/drivers/watchdog/iTCO_wdt.c > @@ -51,6 +51,7 @@ > #define DRV_VERSION "1.11" > > /* Includes */ > +#include /* For ACPI support */ > #include /* For module specific items */ > #include /* For new moduleparam's */ > #include /* For standard types (like size_t) */ > @@ -103,6 +104,8 @@ static struct { /* this is private data > struct platform_device *dev; > /* the PCI-device */ > struct pci_dev *pdev; > + /* whether or not the watchdog has been suspended */ > + bool suspended; > } iTCO_wdt_private; > > /* module parameters */ > @@ -571,12 +574,60 @@ static void iTCO_wdt_shutdown(struct pla > iTCO_wdt_stop(NULL); > } > > +#ifdef CONFIG_PM_SLEEP > +/* > + * Suspend-to-idle requires this, because it stops the ticks and timekeeping, so > + * the watchdog cannot be pinged while in that state. In ACPI sleep states the > + * watchdog is stopped by the platform firmware. > + */ > + > +#ifdef CONFIG_ACPI > +static inline bool need_suspend(void) > +{ > + return acpi_target_system_state() == ACPI_STATE_S0; > +} > +#else > +static inline bool need_suspend(void) { return true; } > +#endif > + > +static int iTCO_wdt_suspend_noirq(struct device *dev) > +{ > + int ret = 0; > + > + iTCO_wdt_private.suspended = false; > + if (watchdog_active(&iTCO_wdt_watchdog_dev) && need_suspend()) { > + ret = iTCO_wdt_stop(&iTCO_wdt_watchdog_dev); > + if (!ret) > + iTCO_wdt_private.suspended = true; > + } > + return ret; > +} > + > +static int iTCO_wdt_resume_noirq(struct device *dev) > +{ > + if (iTCO_wdt_private.suspended) > + iTCO_wdt_start(&iTCO_wdt_watchdog_dev); > + > + return 0; > +} > + > +struct dev_pm_ops iTCO_wdt_pm = { > + .suspend_noirq = iTCO_wdt_suspend_noirq, > + .resume_noirq = iTCO_wdt_resume_noirq, Hi Rafael, This only covers suspend and resume, but not any of the other sleep operations (like SIMPLE_DEV_PM_OPS would do). Is that intentional ? > +}; > + > +#define ITCO_WDT_PM_OPS &iTCO_wdt_pm Checkpatch wants to see (&iTCO_wdt_pm). ERROR: Macros with complex values should be enclosed in parentheses Thanks, Guenter