From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan.wahren@i2se.com (Stefan Wahren) Date: Tue, 1 Dec 2015 22:55:40 +0000 Subject: [PATCH 2/3] pwm: bcm2835: prevent division by zero In-Reply-To: <1449010541-3767-1-git-send-email-stefan.wahren@i2se.com> References: <1449010541-3767-1-git-send-email-stefan.wahren@i2se.com> Message-ID: <1449010541-3767-3-git-send-email-stefan.wahren@i2se.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org It's possible that the pwm clock become an orphan. So better check the result of clk_get_rate in order to prevent a division by zero. Signed-off-by: Stefan Wahren --- 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 174cca9..31a6992 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", -- 1.7.9.5