Commit 097852a1 authored Mar 27, 2020 by Michael Walle Committed by Greg Kroah-Hartman Apr 23, 2020

watchdog: sp805: fix restart handler



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: 6c5c0d48 ("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>

parent a6375c98

drivers/watchdog/sp805_wdt.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -137,10 +137,14 @@ wdt_restart(struct watchdog_device wdd, unsigned long mode, void cmd)
		{
		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;
		}