From: Michael Walle michael@walle.cc
commit ea104a9e4d3e9ebc26fb78dac35585b142ee288b upstream.
The restart handler is missing two things, first, the registers has to be unlocked and second there is no synchronization for the write_relaxed() calls.
This was tested on a custom board with the NXP LS1028A SoC.
Fixes: 6c5c0d48b686c ("watchdog: sp805: add restart handler") Signed-off-by: Michael Walle michael@walle.cc Reviewed-by: Guenter Roeck linux@roeck-us.net Link: https://lore.kernel.org/r/20200327162450.28506-1-michael@walle.cc Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Wim Van Sebroeck wim@linux-watchdog.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/watchdog/sp805_wdt.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/drivers/watchdog/sp805_wdt.c +++ b/drivers/watchdog/sp805_wdt.c @@ -137,10 +137,14 @@ wdt_restart(struct watchdog_device *wdd, { struct sp805_wdt *wdt = watchdog_get_drvdata(wdd);
+ writel_relaxed(UNLOCK, wdt->base + WDTLOCK); writel_relaxed(0, wdt->base + WDTCONTROL); writel_relaxed(0, wdt->base + WDTLOAD); writel_relaxed(INT_ENABLE | RESET_ENABLE, wdt->base + WDTCONTROL);
+ /* Flush posted writes. */ + readl_relaxed(wdt->base + WDTLOCK); + return 0; }