From fd13c14426299e75983a0cd3edf53dfa4083a70a Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Tue, 1 Dec 2015 22:55:40 +0000 Subject: [PATCH] pwm: bcm2835: Prevent division by zero It's possible that the PWM clock becomes an orphan. So better check the result of clk_get_rate() in order to prevent a division by zero. Signed-off-by: Stefan Wahren Reviewed-by: Eric Anholt Signed-off-by: Thierry Reding --- drivers/pwm/pwm-bcm2835.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/pwm/pwm-bcm2835.c b/drivers/pwm/pwm-bcm2835.c index 174cca92f690..31a6992a445c 100644 --- a/drivers/pwm/pwm-bcm2835.c +++ b/drivers/pwm/pwm-bcm2835.c @@ -65,7 +65,15 @@ static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct bcm2835_pwm *pc = to_bcm2835_pwm(chip); - unsigned long scaler = NSEC_PER_SEC / clk_get_rate(pc->clk); + unsigned long rate = clk_get_rate(pc->clk); + unsigned long scaler; + + if (!rate) { + dev_err(pc->dev, "failed to get clock rate\n"); + return -EINVAL; + } + + scaler = NSEC_PER_SEC / rate; if (period_ns <= MIN_PERIOD) { dev_err(pc->dev, "period %d not supported, minimum %d\n", -- 2.20.1