| Message ID | 20240823034314.62305-4-ye.zhang@rock-chips.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] gpio: rockchip: resolve overflow issues | expand |
Am Freitag, 23. August 2024, 05:43:06 CEST schrieb Ye Zhang: > Prevent overflow issues when performing debounce-related calculations. Please add some more explanation here. I.e. something about previous max_debounce calculation does overflow the type of max_debounce Thanks Heiko > Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller") > Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com> > --- > drivers/gpio/gpio-rockchip.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c > index 5f60162baaeb..bf22b103b6a2 100644 > --- a/drivers/gpio/gpio-rockchip.c > +++ b/drivers/gpio/gpio-rockchip.c > @@ -209,11 +209,12 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc, > freq = clk_get_rate(bank->db_clk); > if (!freq) > return -EINVAL; > - max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; > + div = (u64)(GENMASK(23, 0) + 1) * 2 * 1000000; > + max_debounce = DIV_ROUND_CLOSEST_ULL(div, freq); > if (debounce > max_debounce) > return -EINVAL; > > - div = debounce * freq; > + div = (u64)debounce * freq; > div_reg = DIV_ROUND_CLOSEST_ULL(div, 2 * USEC_PER_SEC) - 1; > } else { > div_debounce_support = false; >
在 2024/8/23 11:43, Ye Zhang 写道: > Prevent overflow issues when performing debounce-related calculations. > > Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller") > Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com> > --- > drivers/gpio/gpio-rockchip.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c > index 5f60162baaeb..bf22b103b6a2 100644 > --- a/drivers/gpio/gpio-rockchip.c > +++ b/drivers/gpio/gpio-rockchip.c > @@ -209,11 +209,12 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc, > freq = clk_get_rate(bank->db_clk); > if (!freq) > return -EINVAL; > - max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; > + div = (u64)(GENMASK(23, 0) + 1) * 2 * 1000000; > + max_debounce = DIV_ROUND_CLOSEST_ULL(div, freq); can't max_debounce = DIV_ROUND_CLOSEST_ULL((GENMASK(23, 0) + 1) * 2 * 1000000, freq) work? > if (debounce > max_debounce) > return -EINVAL; > > - div = debounce * freq; > + div = (u64)debounce * freq; > div_reg = DIV_ROUND_CLOSEST_ULL(div, 2 * USEC_PER_SEC) - 1; > } else { > div_debounce_support = false;
On Fri, Aug 23, 2024 at 11:43:06AM +0800, Ye Zhang wrote: > Prevent overflow issues when performing debounce-related calculations. ... > - max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; > + div = (u64)(GENMASK(23, 0) + 1) * 2 * 1000000; You probably want to use HZ_PER_MHZ from units.h or so?
On Fri, Aug 23, 2024 at 06:59:40PM +0800, Shawn Lin wrote: > 在 2024/8/23 11:43, Ye Zhang 写道: ... > > - max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; > > + div = (u64)(GENMASK(23, 0) + 1) * 2 * 1000000; > > + max_debounce = DIV_ROUND_CLOSEST_ULL(div, freq); > > can't max_debounce = DIV_ROUND_CLOSEST_ULL((GENMASK(23, 0) + 1) * 2 * > 1000000, freq) work? Wouldn't be too long line in this case?
diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c index 5f60162baaeb..bf22b103b6a2 100644 --- a/drivers/gpio/gpio-rockchip.c +++ b/drivers/gpio/gpio-rockchip.c @@ -209,11 +209,12 @@ static int rockchip_gpio_set_debounce(struct gpio_chip *gc, freq = clk_get_rate(bank->db_clk); if (!freq) return -EINVAL; - max_debounce = (GENMASK(23, 0) + 1) * 2 * 1000000 / freq; + div = (u64)(GENMASK(23, 0) + 1) * 2 * 1000000; + max_debounce = DIV_ROUND_CLOSEST_ULL(div, freq); if (debounce > max_debounce) return -EINVAL; - div = debounce * freq; + div = (u64)debounce * freq; div_reg = DIV_ROUND_CLOSEST_ULL(div, 2 * USEC_PER_SEC) - 1; } else { div_debounce_support = false;
Prevent overflow issues when performing debounce-related calculations. Fixes: 3bcbd1a85b68 ("gpio/rockchip: support next version gpio controller") Signed-off-by: Ye Zhang <ye.zhang@rock-chips.com> --- drivers/gpio/gpio-rockchip.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)