watchdog: atlas7_wdt: test clock rate to avoid division by 0

The clk API may return 0 on clk_get_rate, so we should check the result before
using it as a divisor.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --git a/drivers/watchdog/atlas7_wdt.c b/drivers/watchdog/atlas7_wdt.c
index df6d9242a319587b3820b3fa621c7aa0d65ef42c..ed80734befae16ea294b97fa6f1bfc5249a5d6bc 100644 (file)
--- a/drivers/watchdog/atlas7_wdt.c
+++ b/drivers/watchdog/atlas7_wdt.c
@@ -154,6 +154,11 @@ static int atlas7_wdt_probe(struct platform_device *pdev)
        writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL);
 
        wdt->tick_rate = clk_get_rate(clk);
+       if (!wdt->tick_rate) {
+               ret = -EINVAL;
+               goto err1;
+       }
+
        wdt->clk = clk;
        atlas7_wdd.min_timeout = 1;
        atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate;