[PATCH v2] gpio: rockchip: resolve underflow issue

From: Ye Zhang
Date: Fri Aug 23 2024 - 09:12:50 EST


div_reg may be < 0 if debounce is zero, causing the unsigned int to
overflow.

Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller")
Signed-off-by: Ye Zhang <ye.zhang@xxxxxxxxxxxxxx>
---
drivers/gpio/gpio-rockchip.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c
index bf22b103b6a2..c3a87d075908 100644
--- a/drivers/gpio/gpio-rockchip.c
+++ b/drivers/gpio/gpio-rockchip.c
@@ -204,8 +204,8 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc,
unsigned int cur_div_reg;
u64 div;

- if (bank->gpio_type == GPIO_TYPE_V2 && !IS_ERR(bank->db_clk)) {
- div_debounce_support = true;
+ div_debounce_support = (bank->gpio_type == GPIO_TYPE_V2) && !IS_ERR(bank->db_clk);
+ if (debounce && div_debounce_support) {
freq = clk_get_rate(bank->db_clk);
if (!freq)
return -EINVAL;
@@ -216,8 +216,6 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc,

div = (u64)debounce * freq;
div_reg = DIV_ROUND_CLOSEST_ULL(div, 2 * USEC_PER_SEC) - 1;
- } else {
- div_debounce_support = false;
}

raw_spin_lock_irqsave(&bank->slock, flags);
--
2.34.1