| Message ID | 20240823034314.62305-2-ye.zhang@rock-chips.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] gpio: rockchip: avoid division by zero | expand |
Am Freitag, 23. August 2024, 05:43:04 CEST schrieb Ye Zhang: > If the clk_get_rate return '0', it will happen division by zero. > > Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller") > Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> > --- > drivers/gpio/gpio-rockchip.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c > index 0bd339813110..712258224eb3 100644 > --- a/drivers/gpio/gpio-rockchip.c > +++ b/drivers/gpio/gpio-rockchip.c > @@ -207,6 +207,8 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc, > if (bank->gpio_type == GPIO_TYPE_V2 && !IS_ERR(bank->db_clk)) { > div_debounce_support = true; > freq = clk_get_rate(bank->db_clk); > + if (!freq) > + return -EINVAL; > max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; > if (debounce > max_debounce) > return -EINVAL; >
On Fri, Aug 23, 2024 at 11:43:04AM +0800, Ye Zhang wrote: > If the clk_get_rate return '0', it will happen division by zero. At the abstraction level this is good to avoid 0 division and return an error, but... > freq = clk_get_rate(bank->db_clk); > + if (!freq) > + return -EINVAL; ...do you this the absence of debounce here is a fatal error? (Yes, I see it's a fatal when it's bigger than maximum.) > max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; > if (debounce > max_debounce) > return -EINVAL;
diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c index 0bd339813110..712258224eb3 100644 --- a/drivers/gpio/gpio-rockchip.c +++ b/drivers/gpio/gpio-rockchip.c @@ -207,6 +207,8 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc, if (bank->gpio_type == GPIO_TYPE_V2 && !IS_ERR(bank->db_clk)) { div_debounce_support = true; freq = clk_get_rate(bank->db_clk); + if (!freq) + return -EINVAL; max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; if (debounce > max_debounce) return -EINVAL;
If the clk_get_rate return '0', it will happen division by zero. Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller") Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com> --- drivers/gpio/gpio-rockchip.c | 2 ++ 1 file changed, 2 insertions(+)