Messages in this thread | | | Date | Wed, 01 Apr 2015 18:21:40 -0700 | From | Guenter Roeck <> | Subject | Re: [PATCH] PM / watchdog: iTCO: stop watchdog during system suspend |
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On 04/01/2015 05:31 PM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > 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 <borun.fu@intel.com> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > 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 <linux/acpi.h> /* For ACPI support */ > #include <linux/module.h> /* For module specific items */ > #include <linux/moduleparam.h> /* For new moduleparam's */ > #include <linux/types.h> /* 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
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