Re: [PATCH] mlxsw: fix warnings for big-endian 32-bit dma_addr_t

Wed, Oct 07, 2015 at 08:53:02AM CEST, joe@perches.com wrote:

On Tue, 2015-10-06 at 23:47 +0200, Arnd Bergmann wrote:

quoted

The recently added mlxsw driver produces warnings in ARM
allmodconfig:

drivers/net/ethernet/mellanox/mlxsw/pci.c: In function 'mlxsw_pci_cmd_exec':
drivers/net/ethernet/mellanox/mlxsw/pci.c:1585:59: warning: right shift count >= width of type [-Wshift-count-overflow]
linux/byteorder/big_endian.h:38:51: note: in definition of macro '__cpu_to_be32'
drivers/net/ethernet/mellanox/mlxsw/pci.c:76:2: note: in expansion of macro 'iowrite32be'

This changes the type of the local variable to u64, which gets rid of the
warning and seems nicer than adding #ifdefs.

Using upper_32_bits instead of the shift might be
nicer than changing the type.

Wasn't aware of this macro. Indeed this looks more appropriate. Thanks!