| Message ID | 20220629084816.125515-2-stephan.gerhold@kernkonzept.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/3] watchdog: pm8916_wdt: Avoid read of write-only PET register | expand |
On Wed, 29 Jun 2022 at 10:48, Stephan Gerhold <stephan.gerhold@kernkonzept.com> wrote: > > PMIC_WD_RESET_PET is a write-only register that is used to ping > the watchdog. It does not make sense to use read-modify-write > for it: a register read will never return anything but zero. > (And actually even if it did we would still want to write again > to ensure the watchdog is pinged.) > > Reduce the overhead for the watchdog ping slightly by using > regmap_write() directly instead. > > Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com> > Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Loic Poulain <loic.poulain@linaro.org> > --- > Changes in v2: Add Guenter's Reviewed-by > --- > drivers/watchdog/pm8916_wdt.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/watchdog/pm8916_wdt.c b/drivers/watchdog/pm8916_wdt.c > index 0937b8d33104..670cd79f4cf9 100644 > --- a/drivers/watchdog/pm8916_wdt.c > +++ b/drivers/watchdog/pm8916_wdt.c > @@ -58,9 +58,8 @@ static int pm8916_wdt_ping(struct watchdog_device *wdev) > { > struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev); > > - return regmap_update_bits(wdt->regmap, > - wdt->baseaddr + PON_PMIC_WD_RESET_PET, > - WATCHDOG_PET_BIT, WATCHDOG_PET_BIT); > + return regmap_write(wdt->regmap, wdt->baseaddr + PON_PMIC_WD_RESET_PET, > + WATCHDOG_PET_BIT); > } > > static int pm8916_wdt_configure_timers(struct watchdog_device *wdev) > -- > 2.30.2 >
diff --git a/drivers/watchdog/pm8916_wdt.c b/drivers/watchdog/pm8916_wdt.c index 0937b8d33104..670cd79f4cf9 100644 --- a/drivers/watchdog/pm8916_wdt.c +++ b/drivers/watchdog/pm8916_wdt.c @@ -58,9 +58,8 @@ static int pm8916_wdt_ping(struct watchdog_device *wdev) { struct pm8916_wdt *wdt = watchdog_get_drvdata(wdev); - return regmap_update_bits(wdt->regmap, - wdt->baseaddr + PON_PMIC_WD_RESET_PET, - WATCHDOG_PET_BIT, WATCHDOG_PET_BIT); + return regmap_write(wdt->regmap, wdt->baseaddr + PON_PMIC_WD_RESET_PET, + WATCHDOG_PET_BIT); } static int pm8916_wdt_configure_timers(struct watchdog_device *wdev)