| Message ID | 20240903073649.237362-2-ye.zhang@rock-chips.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | gpio: rockchip: Update the GPIO driver | expand |
On Tue, Sep 03, 2024 at 03:36:38PM +0800, Ye Zhang wrote: > If the clk_get_rate return '0', it will happen division by zero. I don't understand the circumstances when it may happen. > Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller") Not sure that this actually fixes anything. See below why I think so. ... > if (bank->gpio_type == GPIO_TYPE_V2 && !IS_ERR(bank->db_clk)) { Here you explicitly checked that the clock is provided by DT. ... > freq = clk_get_rate(bank->db_clk); Here you read the frequency which may be 0 in two cases: 1) in DT explicitly set to 0; 2) CCF is disabled. So, wrong DTs have to be validated / fixed beforehand, correct? But if the CCF is disabled, the db_clk is NULL. Moreover I don't see how the db_clk may contain error pointer as you have it filtered out at _get_bank_data(). So, maybe what you need is to have NULL check in the conditional and explaining more in the commit message why it is currently a problematic code? > + if (!freq) > + 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(+)