| Message ID | 20170302173114.28508-5-alexandre.belloni@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 03/02/2017 09:31 AM, Alexandre Belloni wrote: > 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 <alexandre.belloni@free-electrons.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > --- > 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; >
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;
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 <alexandre.belloni@free-electrons.com> --- drivers/watchdog/sama5d4_wdt.c | 5 +++++ 1 file changed, 5 insertions(+)