Re: [PATCH net] net: fs_enet: Fix warning due to wrong type

From: Simon Horman
Date: Fri Aug 09 2024 - 06:01:28 EST


On Thu, Aug 08, 2024 at 09:16:48AM +0200, Christophe Leroy wrote:
> Building fs_enet on powerpc e500 leads to following warning:
>
> CC drivers/net/ethernet/freescale/fs_enet/mac-scc.o
> In file included from ./include/linux/build_bug.h:5,
> from ./include/linux/container_of.h:5,
> from ./include/linux/list.h:5,
> from ./include/linux/module.h:12,
> from drivers/net/ethernet/freescale/fs_enet/mac-scc.c:15:
> drivers/net/ethernet/freescale/fs_enet/mac-scc.c: In function 'allocate_bd':
> ./include/linux/err.h:28:49: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
> 28 | #define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO)
> | ^
> ./include/linux/compiler.h:77:45: note: in definition of macro 'unlikely'
> 77 | # define unlikely(x) __builtin_expect(!!(x), 0)
> | ^
> drivers/net/ethernet/freescale/fs_enet/mac-scc.c:138:13: note: in expansion of macro 'IS_ERR_VALUE'
> 138 | if (IS_ERR_VALUE(fep->ring_mem_addr))
> | ^~~~~~~~~~~~
>
> This is due to fep->ring_mem_addr not being a pointer but a DMA
> address which is 64 bits on that platform while pointers are
> 32 bits as this is a 32 bits platform with wider physical bus.
>
> However, using fep->ring_mem_addr is just wrong because
> cpm_muram_alloc() returns an offset within the muram and not
> a physical address directly. So use fpi->dpram_offset instead.
>
> Fixes: 48257c4f168e ("Add fs_enet ethernet network driver, for several embedded platforms.")
> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>