RE: [PATCH] staging: pi433: using div64_u64() instead of do_div()

From: David Laight
Date: Fri Jan 21 2022 - 08:34:25 EST


From: Jiapeng Chong
> Sent: 21 January 2022 11:50
> Subject: [PATCH] staging: pi433: using div64_u64() instead of do_div()
>
> Clean the following coccicheck warning:
>
> ./drivers/staging/pi433/rf69.c:286:1-7: WARNING: do_div() does a
> 64-by-32 division, please consider using div64_u64 instead.

That is one of patchcheck's worse warnings.

You need to check the domain of the divisor, not its type.

do_div() exists to avoid expensive 64bit divides when the
divisor is small.

David

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