2016-03-02 22:59:33

by Wolfram Sang

[permalink] [raw]
Subject: [PATCH v2] pwm: pwm-lpc18xx-sct: test clock rate to avoid division by 0

From: Wolfram Sang <[email protected]>

The clk API may return 0 on clk_get_rate, so we should check the result before
using it as a divisor.

Signed-off-by: Wolfram Sang <[email protected]>
---
drivers/pwm/pwm-lpc18xx-sct.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
index 9163085101bc94..9861fed4e67d04 100644
--- a/drivers/pwm/pwm-lpc18xx-sct.c
+++ b/drivers/pwm/pwm-lpc18xx-sct.c
@@ -360,6 +360,11 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
}

lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk);
+ if (!lpc18xx_pwm->clk_rate) {
+ dev_err(&pdev->dev, "pwm clock has no frequency\n");
+ ret = -EINVAL;
+ goto disable_pwmclk;
+ }

mutex_init(&lpc18xx_pwm->res_lock);
mutex_init(&lpc18xx_pwm->period_lock);
--
2.7.0


2016-03-02 23:28:32

by Joachim Eastwood

[permalink] [raw]
Subject: Re: [PATCH v2] pwm: pwm-lpc18xx-sct: test clock rate to avoid division by 0

Hi Wolfram,

On 2 March 2016 at 23:57, Wolfram Sang <[email protected]> wrote:
> From: Wolfram Sang <[email protected]>
>
> The clk API may return 0 on clk_get_rate, so we should check the result before
> using it as a divisor.
>
> Signed-off-by: Wolfram Sang <[email protected]>
> ---
> drivers/pwm/pwm-lpc18xx-sct.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/pwm/pwm-lpc18xx-sct.c b/drivers/pwm/pwm-lpc18xx-sct.c
> index 9163085101bc94..9861fed4e67d04 100644
> --- a/drivers/pwm/pwm-lpc18xx-sct.c
> +++ b/drivers/pwm/pwm-lpc18xx-sct.c
> @@ -360,6 +360,11 @@ static int lpc18xx_pwm_probe(struct platform_device *pdev)
> }
>
> lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk);
> + if (!lpc18xx_pwm->clk_rate) {
> + dev_err(&pdev->dev, "pwm clock has no frequency\n");
> + ret = -EINVAL;
> + goto disable_pwmclk;
> + }

Acked-by: Joachim Eastwood <[email protected]>

Thanks for fixing this.


regards,
Joachim Eastwood

2016-03-04 15:05:52

by Thierry Reding

[permalink] [raw]
Subject: Re: [PATCH v2] pwm: pwm-lpc18xx-sct: test clock rate to avoid division by 0

On Wed, Mar 02, 2016 at 11:57:09PM +0100, Wolfram Sang wrote:
> From: Wolfram Sang <[email protected]>
>
> The clk API may return 0 on clk_get_rate, so we should check the result before
> using it as a divisor.
>
> Signed-off-by: Wolfram Sang <[email protected]>
> ---
> drivers/pwm/pwm-lpc18xx-sct.c | 5 +++++
> 1 file changed, 5 insertions(+)

Applied, thanks.

Thierry

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