2020-05-20 10:35:30

by Qii Wang (王琪)

[permalink] [raw]
Subject: [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels

From: Qii Wang <[email protected]>

Use div_u64 for 64-bit division, and change sample_ns type to
unsigned int. Otherwise, the module will reference __udivdi3
under 32-bit kernels, which is not allowed in kernel space.

Signed-off-by: Qii Wang <[email protected]>
---
drivers/i2c/busses/i2c-mt65xx.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 7020618..deef69e 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -551,7 +551,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
const struct i2c_spec_values *spec;
unsigned int su_sta_cnt, low_cnt, high_cnt, max_step_cnt;
unsigned int sda_max, sda_min, clk_ns, max_sta_cnt = 0x3f;
- long long sample_ns = (1000000000 * (sample_cnt + 1)) / clk_src;
+ unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1),
+ clk_src);

if (!i2c->dev_comp->timing_adjust)
return 0;
--
1.9.1


2020-05-20 13:31:46

by Wolfram Sang

[permalink] [raw]
Subject: Re: [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels

On Wed, May 20, 2020 at 06:31:53PM +0800, [email protected] wrote:
> From: Qii Wang <[email protected]>
>
> Use div_u64 for 64-bit division, and change sample_ns type to
> unsigned int. Otherwise, the module will reference __udivdi3
> under 32-bit kernels, which is not allowed in kernel space.
>
> Signed-off-by: Qii Wang <[email protected]>

Applied to for-next by squashing it into the relevant commit, thanks!

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2020-05-20 16:17:00

by Randy Dunlap

[permalink] [raw]
Subject: Re: [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels

On 5/20/20 3:31 AM, [email protected] wrote:
> From: Qii Wang <[email protected]>
>
> Use div_u64 for 64-bit division, and change sample_ns type to
> unsigned int. Otherwise, the module will reference __udivdi3
> under 32-bit kernels, which is not allowed in kernel space.
>
> Signed-off-by: Qii Wang <[email protected]>

Acked-by: Randy Dunlap <[email protected]> # build-tested

thanks.

> ---
> drivers/i2c/busses/i2c-mt65xx.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index 7020618..deef69e 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -551,7 +551,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
> const struct i2c_spec_values *spec;
> unsigned int su_sta_cnt, low_cnt, high_cnt, max_step_cnt;
> unsigned int sda_max, sda_min, clk_ns, max_sta_cnt = 0x3f;
> - long long sample_ns = (1000000000 * (sample_cnt + 1)) / clk_src;
> + unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1),
> + clk_src);
>
> if (!i2c->dev_comp->timing_adjust)
> return 0;
>


--
~Randy