Merge tag 'irqchip-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip updates for 4.16-rc2 from Marc Zyngier

 - A MIPS GIC fix for spurious, masked interrupts
 - A fix for a subtle IPI bug in GICv3
 - Do not probe GICv3 ITSs that are marked as disabled
 - Multi-MSI support for GICv2m
 - Various cleanups

1 files changed, 21 insertions, 13 deletions

diff --git a/drivers/watchdog/mt7621_wdt.c b/drivers/watchdog/mt7621_wdt.c
index db38f8017218..5c4a764717c4 100644
--- a/drivers/watchdog/mt7621_wdt.c
+++ b/drivers/watchdog/mt7621_wdt.c
@@ -105,6 +105,11 @@ static int mt7621_wdt_bootcause(void)
 	return 0;
 }
 
+static int mt7621_wdt_is_running(struct watchdog_device *w)
+{
+	return !!(rt_wdt_r32(TIMER_REG_TMR1CTL) & TMR1CTL_ENABLE);
+}
+
 static const struct watchdog_info mt7621_wdt_info = {
 	.identity = "Mediatek Watchdog",
 	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
@@ -128,7 +133,6 @@ static struct watchdog_device mt7621_wdt_dev = {
 static int mt7621_wdt_probe(struct platform_device *pdev)
 {
 	struct resource *res;
-	int ret;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res);
@@ -144,17 +148,22 @@ static int mt7621_wdt_probe(struct platform_device *pdev)
 	watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout,
 			      &pdev->dev);
 	watchdog_set_nowayout(&mt7621_wdt_dev, nowayout);
-
-	ret = watchdog_register_device(&mt7621_wdt_dev);
-
-	return 0;
-}
-
-static int mt7621_wdt_remove(struct platform_device *pdev)
-{
-	watchdog_unregister_device(&mt7621_wdt_dev);
-
-	return 0;
+	if (mt7621_wdt_is_running(&mt7621_wdt_dev)) {
+		/*
+		 * Make sure to apply timeout from watchdog core, taking
+		 * the prescaler of this driver here into account (the
+		 * boot loader might be using a different prescaler).
+		 *
+		 * To avoid spurious resets because of different scaling,
+		 * we first disable the watchdog, set the new prescaler
+		 * and timeout, and then re-enable the watchdog.
+		 */
+		mt7621_wdt_stop(&mt7621_wdt_dev);
+		mt7621_wdt_start(&mt7621_wdt_dev);
+		set_bit(WDOG_HW_RUNNING, &mt7621_wdt_dev.status);
+	}
+
+	return devm_watchdog_register_device(&pdev->dev, &mt7621_wdt_dev);
 }
 
 static void mt7621_wdt_shutdown(struct platform_device *pdev)
@@ -170,7 +179,6 @@ MODULE_DEVICE_TABLE(of, mt7621_wdt_match);
 
 static struct platform_driver mt7621_wdt_driver = {
 	.probe		= mt7621_wdt_probe,
-	.remove		= mt7621_wdt_remove,
 	.shutdown	= mt7621_wdt_shutdown,
 	.driver		= {
 		.name		= KBUILD_MODNAME,