# Re: \[PATCH\] sfc\_ef100: Fix build failure on powerpc

- From: Segher Boessenkool \<hidden\>
- Date: 2020-08-13 15:58:00 
- List: netdev
- Page: https://ratatoskr.run/netdev/2020/08/6067835
- Thread: https://ratatoskr.run/netdev/2020/08/6067780/t.md

```text
On Thu, Aug 13, 2020 at 02:39:10PM +0000, Christophe Leroy wrote:
> ppc6xx_defconfig fails building sfc.ko module, complaining
> about the lack of _umoddi3 symbol.
> 
> This is due to the following test
> 
>  		if (EFX_MIN_DMAQ_SIZE % reader->value) {
> 
> Because reader->value is u64.
> 
> As EFX_MIN_DMAQ_SIZE value is 512, reader->value is obviously small
> enough for an u32 calculation, so cast it as (u32) for the test, to
> avoid the need for _umoddi3.

That isn't the same e.g. if reader->value is 2**32 + small.  Which
probably cannot happen, but :-)


Segher
```