If the watchdog is already running during probe use its pre-configured
timeout instead of a default timeout to make sure the watchdog is pinged
in time until userspace takes over.
Signed-off-by: Stefan Riedmueller <[email protected]>
---
drivers/watchdog/da9063_wdt.c | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
index 3d65e92a4e3f..34d0c4f03814 100644
--- a/drivers/watchdog/da9063_wdt.c
+++ b/drivers/watchdog/da9063_wdt.c
@@ -46,15 +46,16 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
}
/*
- * Return 0 if watchdog is disabled, else non zero.
+ * Read the currently active timeout.
+ * Zero means the watchdog is disabled.
*/
-static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
+static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063)
{
unsigned int val;
regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
- return val & DA9063_TWDSCALE_MASK;
+ return wdt_timeout[val & DA9063_TWDSCALE_MASK];
}
static int da9063_wdt_disable_timer(struct da9063 *da9063)
@@ -191,6 +192,7 @@ static int da9063_wdt_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct da9063 *da9063;
struct watchdog_device *wdd;
+ int timeout;
if (!dev->parent)
return -EINVAL;
@@ -214,15 +216,20 @@ static int da9063_wdt_probe(struct platform_device *pdev)
watchdog_set_restart_priority(wdd, 128);
watchdog_set_drvdata(wdd, da9063);
- /* Set default timeout, maybe override it with DT value, scale it */
- wdd->timeout = DA9063_WDG_TIMEOUT;
- watchdog_init_timeout(wdd, 0, dev);
- da9063_wdt_set_timeout(wdd, wdd->timeout);
-
- /* Change the timeout to the default value if the watchdog is running */
- if (da9063_wdt_is_running(da9063)) {
- da9063_wdt_update_timeout(da9063, wdd->timeout);
+ /*
+ * Use pre-configured timeout if watchdog is already running.
+ * Otherwise set default timeout, maybe override it with DT value,
+ * scale it
+ */
+ timeout = da9063_wdt_read_timeout(da9063);
+ if (timeout) {
+ wdd->timeout = timeout;
set_bit(WDOG_HW_RUNNING, &wdd->status);
+ dev_info(da9063->dev, "watchdog is running (%u s)", timeout);
+ } else {
+ wdd->timeout = DA9063_WDG_TIMEOUT;
+ watchdog_init_timeout(wdd, 0, dev);
+ da9063_wdt_set_timeout(wdd, wdd->timeout);
}
return devm_watchdog_register_device(dev, wdd);
--
2.23.0
On 26 March 2020 15:02, Stefan Riedmueller wrote:
> If the watchdog is already running during probe use its pre-configured
> timeout instead of a default timeout to make sure the watchdog is pinged
> in time until userspace takes over.
At least for this driver I don't think there's an issue here with regards to
not pinging in time. Calling 'da9063_wdt_update_timeout()', as it currently
does in the probe() when the watchdog is already active, actually disables the
watchdog before then setting a new timeout value, so by that method we're
avoiding a timeout and starting a new timer period.
To my mind the timeout value should come from DT if possible, which I would
assume for the most part would match whatever is defined in the bootloader as
well, unless I'm mistaken. If that's not available though then I would maybe
agree on falling back to a value that was already programmed in the bootloader
rather than the driver default which should be the last resort.
>
> Signed-off-by: Stefan Riedmueller <[email protected]>
> ---
> drivers/watchdog/da9063_wdt.c | 29 ++++++++++++++++++-----------
> 1 file changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
> index 3d65e92a4e3f..34d0c4f03814 100644
> --- a/drivers/watchdog/da9063_wdt.c
> +++ b/drivers/watchdog/da9063_wdt.c
> @@ -46,15 +46,16 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned
> int secs)
> }
>
> /*
> - * Return 0 if watchdog is disabled, else non zero.
> + * Read the currently active timeout.
> + * Zero means the watchdog is disabled.
> */
> -static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
> +static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063)
> {
> unsigned int val;
>
> regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
>
> - return val & DA9063_TWDSCALE_MASK;
> + return wdt_timeout[val & DA9063_TWDSCALE_MASK];
> }
>
> static int da9063_wdt_disable_timer(struct da9063 *da9063)
> @@ -191,6 +192,7 @@ static int da9063_wdt_probe(struct platform_device
> *pdev)
> struct device *dev = &pdev->dev;
> struct da9063 *da9063;
> struct watchdog_device *wdd;
> + int timeout;
>
> if (!dev->parent)
> return -EINVAL;
> @@ -214,15 +216,20 @@ static int da9063_wdt_probe(struct platform_device
> *pdev)
> watchdog_set_restart_priority(wdd, 128);
> watchdog_set_drvdata(wdd, da9063);
>
> - /* Set default timeout, maybe override it with DT value, scale it */
> - wdd->timeout = DA9063_WDG_TIMEOUT;
> - watchdog_init_timeout(wdd, 0, dev);
> - da9063_wdt_set_timeout(wdd, wdd->timeout);
> -
> - /* Change the timeout to the default value if the watchdog is running */
> - if (da9063_wdt_is_running(da9063)) {
> - da9063_wdt_update_timeout(da9063, wdd->timeout);
> + /*
> + * Use pre-configured timeout if watchdog is already running.
> + * Otherwise set default timeout, maybe override it with DT value,
> + * scale it
> + */
> + timeout = da9063_wdt_read_timeout(da9063);
> + if (timeout) {
> + wdd->timeout = timeout;
> set_bit(WDOG_HW_RUNNING, &wdd->status);
> + dev_info(da9063->dev, "watchdog is running (%u s)", timeout);
> + } else {
> + wdd->timeout = DA9063_WDG_TIMEOUT;
> + watchdog_init_timeout(wdd, 0, dev);
> + da9063_wdt_set_timeout(wdd, wdd->timeout);
> }
>
> return devm_watchdog_register_device(dev, wdd);
> --
> 2.23.0
On 3/30/20 9:38 AM, Adam Thomson wrote:
> On 26 March 2020 15:02, Stefan Riedmueller wrote:
>
>> If the watchdog is already running during probe use its pre-configured
>> timeout instead of a default timeout to make sure the watchdog is pinged
>> in time until userspace takes over.
>
> At least for this driver I don't think there's an issue here with regards to
> not pinging in time. Calling 'da9063_wdt_update_timeout()', as it currently
> does in the probe() when the watchdog is already active, actually disables the
> watchdog before then setting a new timeout value, so by that method we're
> avoiding a timeout and starting a new timer period.
>
> To my mind the timeout value should come from DT if possible, which I would
> assume for the most part would match whatever is defined in the bootloader as
> well, unless I'm mistaken. If that's not available though then I would maybe
> agree on falling back to a value that was already programmed in the bootloader
> rather than the driver default which should be the last resort.
>
Agreed.
Guenter
>>
>> Signed-off-by: Stefan Riedmueller <[email protected]>
>> ---
>> drivers/watchdog/da9063_wdt.c | 29 ++++++++++++++++++-----------
>> 1 file changed, 18 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
>> index 3d65e92a4e3f..34d0c4f03814 100644
>> --- a/drivers/watchdog/da9063_wdt.c
>> +++ b/drivers/watchdog/da9063_wdt.c
>> @@ -46,15 +46,16 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned
>> int secs)
>> }
>>
>> /*
>> - * Return 0 if watchdog is disabled, else non zero.
>> + * Read the currently active timeout.
>> + * Zero means the watchdog is disabled.
>> */
>> -static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
>> +static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063)
>> {
>> unsigned int val;
>>
>> regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
>>
>> - return val & DA9063_TWDSCALE_MASK;
>> + return wdt_timeout[val & DA9063_TWDSCALE_MASK];
>> }
>>
>> static int da9063_wdt_disable_timer(struct da9063 *da9063)
>> @@ -191,6 +192,7 @@ static int da9063_wdt_probe(struct platform_device
>> *pdev)
>> struct device *dev = &pdev->dev;
>> struct da9063 *da9063;
>> struct watchdog_device *wdd;
>> + int timeout;
>>
>> if (!dev->parent)
>> return -EINVAL;
>> @@ -214,15 +216,20 @@ static int da9063_wdt_probe(struct platform_device
>> *pdev)
>> watchdog_set_restart_priority(wdd, 128);
>> watchdog_set_drvdata(wdd, da9063);
>>
>> - /* Set default timeout, maybe override it with DT value, scale it */
>> - wdd->timeout = DA9063_WDG_TIMEOUT;
>> - watchdog_init_timeout(wdd, 0, dev);
>> - da9063_wdt_set_timeout(wdd, wdd->timeout);
>> -
>> - /* Change the timeout to the default value if the watchdog is running */
>> - if (da9063_wdt_is_running(da9063)) {
>> - da9063_wdt_update_timeout(da9063, wdd->timeout);
>> + /*
>> + * Use pre-configured timeout if watchdog is already running.
>> + * Otherwise set default timeout, maybe override it with DT value,
>> + * scale it
>> + */
>> + timeout = da9063_wdt_read_timeout(da9063);
>> + if (timeout) {
>> + wdd->timeout = timeout;
>> set_bit(WDOG_HW_RUNNING, &wdd->status);
>> + dev_info(da9063->dev, "watchdog is running (%u s)", timeout);
>> + } else {
>> + wdd->timeout = DA9063_WDG_TIMEOUT;
>> + watchdog_init_timeout(wdd, 0, dev);
>> + da9063_wdt_set_timeout(wdd, wdd->timeout);
>> }
>>
>> return devm_watchdog_register_device(dev, wdd);
>> --
>> 2.23.0
>
Hi Guenter, Adam,
Guenter Roeck <[email protected]> wrote on Tue, 31. Mar 20 09:08:
> On 3/30/20 9:38 AM, Adam Thomson wrote:
> > On 26 March 2020 15:02, Stefan Riedmueller wrote:
> >
> >> If the watchdog is already running during probe use its pre-configured
> >> timeout instead of a default timeout to make sure the watchdog is pinged
> >> in time until userspace takes over.
> >
> > At least for this driver I don't think there's an issue here with regards to
> > not pinging in time. Calling 'da9063_wdt_update_timeout()', as it currently
> > does in the probe() when the watchdog is already active, actually disables the
> > watchdog before then setting a new timeout value, so by that method we're
> > avoiding a timeout and starting a new timer period.
> >
> > To my mind the timeout value should come from DT if possible, which I would
> > assume for the most part would match whatever is defined in the bootloader as
> > well, unless I'm mistaken. If that's not available though then I would maybe
> > agree on falling back to a value that was already programmed in the bootloader
> > rather than the driver default which should be the last resort.
> >
> Agreed.
Thanks for both your feedback. I'll drop the pre-configured timeout part and
stick with the default timeout and do the same procedure (init_timeout +
update_timeout) for the da9062.
Thanks
Stefan
>
> Guenter
>
> >>
> >> Signed-off-by: Stefan Riedmueller <[email protected]>
> >> ---
> >> drivers/watchdog/da9063_wdt.c | 29 ++++++++++++++++++-----------
> >> 1 file changed, 18 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/watchdog/da9063_wdt.c b/drivers/watchdog/da9063_wdt.c
> >> index 3d65e92a4e3f..34d0c4f03814 100644
> >> --- a/drivers/watchdog/da9063_wdt.c
> >> +++ b/drivers/watchdog/da9063_wdt.c
> >> @@ -46,15 +46,16 @@ static unsigned int da9063_wdt_timeout_to_sel(unsigned
> >> int secs)
> >> }
> >>
> >> /*
> >> - * Return 0 if watchdog is disabled, else non zero.
> >> + * Read the currently active timeout.
> >> + * Zero means the watchdog is disabled.
> >> */
> >> -static unsigned int da9063_wdt_is_running(struct da9063 *da9063)
> >> +static unsigned int da9063_wdt_read_timeout(struct da9063 *da9063)
> >> {
> >> unsigned int val;
> >>
> >> regmap_read(da9063->regmap, DA9063_REG_CONTROL_D, &val);
> >>
> >> - return val & DA9063_TWDSCALE_MASK;
> >> + return wdt_timeout[val & DA9063_TWDSCALE_MASK];
> >> }
> >>
> >> static int da9063_wdt_disable_timer(struct da9063 *da9063)
> >> @@ -191,6 +192,7 @@ static int da9063_wdt_probe(struct platform_device
> >> *pdev)
> >> struct device *dev = &pdev->dev;
> >> struct da9063 *da9063;
> >> struct watchdog_device *wdd;
> >> + int timeout;
> >>
> >> if (!dev->parent)
> >> return -EINVAL;
> >> @@ -214,15 +216,20 @@ static int da9063_wdt_probe(struct platform_device
> >> *pdev)
> >> watchdog_set_restart_priority(wdd, 128);
> >> watchdog_set_drvdata(wdd, da9063);
> >>
> >> - /* Set default timeout, maybe override it with DT value, scale it */
> >> - wdd->timeout = DA9063_WDG_TIMEOUT;
> >> - watchdog_init_timeout(wdd, 0, dev);
> >> - da9063_wdt_set_timeout(wdd, wdd->timeout);
> >> -
> >> - /* Change the timeout to the default value if the watchdog is running */
> >> - if (da9063_wdt_is_running(da9063)) {
> >> - da9063_wdt_update_timeout(da9063, wdd->timeout);
> >> + /*
> >> + * Use pre-configured timeout if watchdog is already running.
> >> + * Otherwise set default timeout, maybe override it with DT value,
> >> + * scale it
> >> + */
> >> + timeout = da9063_wdt_read_timeout(da9063);
> >> + if (timeout) {
> >> + wdd->timeout = timeout;
> >> set_bit(WDOG_HW_RUNNING, &wdd->status);
> >> + dev_info(da9063->dev, "watchdog is running (%u s)", timeout);
> >> + } else {
> >> + wdd->timeout = DA9063_WDG_TIMEOUT;
> >> + watchdog_init_timeout(wdd, 0, dev);
> >> + da9063_wdt_set_timeout(wdd, wdd->timeout);
> >> }
> >>
> >> return devm_watchdog_register_device(dev, wdd);
> >> --
> >> 2.23.0
> >
>