Commit 4e5b4065 authored by Stephan Gerhold's avatar Stephan Gerhold Committed by Wim Van Sebroeck
Browse files

watchdog: pm8916_wdt: Avoid read of write-only PET register 



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: default avatarStephan Gerhold <stephan.gerhold@kernkonzept.com>
Reviewed-by: default avatarLoic Poulain <loic.poulain@linaro.org>
Reviewed-by: default avatarGuenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220629084816.125515-2-stephan.gerhold@kernkonzept.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarWim Van Sebroeck <wim@linux-watchdog.org>
parent 5f02d033

drivers/watchdog/pm8916_wdt.c

+2 −3
Original line number Diff line number Diff line
@@ -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)