Sorry, my fault. It should work as well.
-----Original Message-----
From: Guenter Roeck [mailto:[email protected]]
Sent: Thursday, April 02, 2015 9:11
To: Fu, Borun; Rafael J. Wysocki; [email protected]
Cc: Linux Kernel Mailing List; Linux PM list; Wim Van Sebroeck; Li, Aubrey;
Wang, Frank
Subject: Re: [PATCH] PM / watchdog: iTCO: stop watchdog during system suspend
On 04/01/2015 05:52 PM, Fu, Borun wrote:
> Hi Rafael,
> watchdog_active() function is not implemented in your patch. Pls. add it.
>
Please explain why using the standard watchdog_active() would not work here.
Guenter
> static int watchdog_active(struct device *dev) {
> unsigned int val;
>
> spin_lock(&iTCO_wdt_private.io_lock);
> val = inw(TCO1_CNT);
> spin_unlock(&iTCO_wdt_private.io_lock);
>
> /* Bit 11: TCO Timer Halt */
> if (val & 0x0800)
> return 0;
> else
> return 1;
> }
>
> Regards,
> Borun
> -----Original Message-----
> From: Rafael J. Wysocki [mailto:[email protected]]
> Sent: Thursday, April 02, 2015 8:31
> To: [email protected]
> Cc: Linux Kernel Mailing List; Linux PM list; Wim Van Sebroeck; Li,
> Aubrey; Fu, Borun
> Subject: [PATCH] PM / watchdog: iTCO: stop watchdog during system
> suspend
>
> From: Rafael J. Wysocki <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> ---
> 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, };
> +
> +#define ITCO_WDT_PM_OPS &iTCO_wdt_pm
> +#else
> +#define ITCO_WDT_PM_OPS NULL
> +#endif /* CONFIG_PM_SLEEP */
> +
> static struct platform_driver iTCO_wdt_driver = {
> .probe = iTCO_wdt_probe,
> .remove = iTCO_wdt_remove,
> .shutdown = iTCO_wdt_shutdown,
> .driver = {
> .name = DRV_NAME,
> + .pm = ITCO_WDT_PM_OPS,
> },
> };
>
>
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