[PATCH v2] watchdog: tangox_wdt: test clock rate to avoid division by 0

Wolfram Sang
2016-03-03T08:24:22Z

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

The clk API may return 0 on clk_get_rate, so we should check the result before
using it as a divisor. For this, refactor the code to use a central
error path.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
drivers/watchdog/tangox_wdt.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/watchdog/tangox_wdt.c b/drivers/watchdog/tangox_wdt.c
index 709c1ed6fd79b9..cfbed7e051b619 100644
--- a/drivers/watchdog/tangox_wdt.c
+++ b/drivers/watchdog/tangox_wdt.c
@@ -139,6 +139,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
return err;

dev->clk_rate = clk_get_rate(dev->clk);
+ if (!dev->clk_rate) {
+ err = -EINVAL;
+ goto err;
+ }

dev->wdt.parent = &pdev->dev;
dev->wdt.info = &tangox_wdt_info;
@@ -171,10 +175,8 @@ static int tangox_wdt_probe(struct platform_device *pdev)
}

err = watchdog_register_device(&dev->wdt);
- if (err) {
- clk_disable_unprepare(dev->clk);
- return err;
- }
+ if (err)
+ goto err;

platform_set_drvdata(pdev, dev);

@@ -187,6 +189,10 @@ static int tangox_wdt_probe(struct platform_device *pdev)
dev_info(&pdev->dev, "SMP86xx/SMP87xx watchdog registered\n");

return 0;
+
+ err:
+ clk_disable_unprepare(dev->clk);
+ return err;
}

static int tangox_wdt_remove(struct platform_device *pdev)
--
2.7.0