* [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels
@ 2020-05-20 10:31 qii.wang
2020-05-20 13:29 ` Wolfram Sang
2020-05-20 16:15 ` Randy Dunlap
0 siblings, 2 replies; 3+ messages in thread
From: qii.wang @ 2020-05-20 10:31 UTC (permalink / raw)
To: wsa
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-kernel,
linux-mediatek, srv_heupstream, leilk.liu, qii.wang
From: Qii Wang <qii.wang@mediatek.com>
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@mediatek.com>
---
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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels
2020-05-20 10:31 [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels qii.wang
@ 2020-05-20 13:29 ` Wolfram Sang
2020-05-20 16:15 ` Randy Dunlap
1 sibling, 0 replies; 3+ messages in thread
From: Wolfram Sang @ 2020-05-20 13:29 UTC (permalink / raw)
To: qii.wang
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-kernel,
linux-mediatek, srv_heupstream, leilk.liu
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On Wed, May 20, 2020 at 06:31:53PM +0800, qii.wang@mediatek.com wrote:
> From: Qii Wang <qii.wang@mediatek.com>
>
> 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@mediatek.com>
Applied to for-next by squashing it into the relevant commit, thanks!
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels
2020-05-20 10:31 [next] i2c: mediatek: Use div_u64 for 64-bit division to fix 32-bit kernels qii.wang
2020-05-20 13:29 ` Wolfram Sang
@ 2020-05-20 16:15 ` Randy Dunlap
1 sibling, 0 replies; 3+ messages in thread
From: Randy Dunlap @ 2020-05-20 16:15 UTC (permalink / raw)
To: qii.wang, wsa
Cc: linux-i2c, devicetree, linux-arm-kernel, linux-kernel,
linux-mediatek, srv_heupstream, leilk.liu
On 5/20/20 3:31 AM, qii.wang@mediatek.com wrote:
> From: Qii Wang <qii.wang@mediatek.com>
>
> 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@mediatek.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # 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
^ permalink raw reply [flat|nested] 3+ messages in thread
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