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

From: Randy Dunlap
Date: Wed May 20 2020 - 12:15:15 EST


On 5/20/20 3:31 AM, qii.wang@xxxxxxxxxxxx wrote:
> From: Qii Wang <qii.wang@xxxxxxxxxxxx>
>
> 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 <qii.wang@xxxxxxxxxxxx>

Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # 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