From mboxrd@z Thu Jan 1 00:00:00 1970 From: rmk+kernel@arm.linux.org.uk (Russell King) Date: Tue, 18 Jun 2013 17:20:32 +0100 Subject: [PATCH 2/2] Watchdog: fix clearing of the watchdog interrupt Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The bits in BRIDGE_CAUSE are documented as RW0C - read, write 0 to clear. If we read the register, mask off the watchdog bit, and write it back, we're actually clearing every interrupt which wasn't pending at the time we read the register - and that is racy. Fix this to only write ~WATCHDOG_BIT to the register, which means we write as zero only the watchdog bit. Signed-off-by: Russell King --- drivers/watchdog/orion_wdt.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/orion_wdt.c b/drivers/watchdog/orion_wdt.c index 4074244..4ea5fcc 100644 --- a/drivers/watchdog/orion_wdt.c +++ b/drivers/watchdog/orion_wdt.c @@ -70,9 +70,7 @@ static int orion_wdt_start(struct watchdog_device *wdt_dev) writel(wdt_tclk * wdt_dev->timeout, wdt_reg + WDT_VAL); /* Clear watchdog timer interrupt */ - reg = readl(BRIDGE_CAUSE); - reg &= ~WDT_INT_REQ; - writel(reg, BRIDGE_CAUSE); + writel(~WDT_INT_REQ, BRIDGE_CAUSE); /* Enable watchdog timer */ reg = readl(wdt_reg + TIMER_CTRL); -- 1.7.4.4