[PATCH v2 2/5] watchdog: renesas_wdt: check rate also for upper limit

[Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>]

When checking the clock rate, ensure also that counting all 16 bits
takes at least one second to match the granularity of the framework.

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
 drivers/watchdog/renesas_wdt.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/renesas_wdt.c b/drivers/watchdog/renesas_wdt.c
index 22b0348826deb1..8437dd52153208 100644
--- a/drivers/watchdog/renesas_wdt.c
+++ b/drivers/watchdog/renesas_wdt.c
@@ -134,14 +134,14 @@ static int rwdt_probe(struct platform_device *pdev)
 
 	for (i = ARRAY_SIZE(clk_divs) - 1; i >= 0; i--) {
 		clks_per_sec = DIV_ROUND_UP(rate, clk_divs[i]);
-		if (clks_per_sec) {
+		if (clks_per_sec && clks_per_sec < 65536) {
 			priv->clks_per_sec = clks_per_sec;
 			priv->cks = i;
 			break;
 		}
 	}
 
-	if (!clks_per_sec) {
+	if (i < 0) {
 		dev_err(&pdev->dev, "Can't find suitable clock divider\n");
 		return -ERANGE;
 	}
-- 
2.11.0