From: Boris BREZILLON Date: Thu, 18 Dec 2014 20:05:30 +0000 (+0100) Subject: pwm: atmel-hlcdc: Prevent division by zero X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=df6922adec987b1c7f07870a00f899fbc9a7d4cc;p=openwrt%2Fstaging%2Fblogic.git pwm: atmel-hlcdc: Prevent division by zero The slow and system clock should never return a rate of zero, but this might happen if the clocks property defined in the DT is referencing the wrong clocks. Prevent any division by zero from happening by testing the clk_freq value before calling do_div(). Signed-off-by: Boris Brezillon Signed-off-by: Thierry Reding --- diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c index e7a785fadcdf..522f7075bb1a 100644 --- a/drivers/pwm/pwm-atmel-hlcdc.c +++ b/drivers/pwm/pwm-atmel-hlcdc.c @@ -64,6 +64,9 @@ static int atmel_hlcdc_pwm_config(struct pwm_chip *c, if (!chip->errata || !chip->errata->slow_clk_erratum) { clk_freq = clk_get_rate(new_clk); + if (!clk_freq) + return -EINVAL; + clk_period_ns = (u64)NSEC_PER_SEC * 256; do_div(clk_period_ns, clk_freq); } @@ -73,6 +76,9 @@ static int atmel_hlcdc_pwm_config(struct pwm_chip *c, clk_period_ns > period_ns) { new_clk = hlcdc->sys_clk; clk_freq = clk_get_rate(new_clk); + if (!clk_freq) + return -EINVAL; + clk_period_ns = (u64)NSEC_PER_SEC * 256; do_div(clk_period_ns, clk_freq); }