Re: [PATCH] net: ezchip: adapt driver to little endian architecture

[Arnd Bergmann <arnd@arndb.de>]

On Friday 26 February 2016 22:05:09 Lada Trimasova wrote:
> 
> @@ -75,6 +86,7 @@ struct nps_enet_rx_ctl {
>                  * nr:  Length in bytes of Rx frame loaded by MAC to Rx buffer
>                  */
>                 struct {
> +#ifdef CONFIG_CPU_BIG_ENDIAN
>                         u32
>                         __reserved_1:16,
>                         cr:1,
> @@ -82,6 +94,15 @@ struct nps_enet_rx_ctl {
>                         crc:1,
>                         __reserved_2:2,
>                         nr:11;
> +#else
> +                       u32
> +                       nr:11,
> +                       __reserved_2:2,
> +                       crc:1,
> +                       er:1,
> +                       cr:1,
> +                       __reserved_1:16;
> +#endif
>                 };

A nicer way to do this would be to remove all the bitfields
and use named constants for accessing the fields insode of
a u32 or u64 variable.

The order of the bits in a bit field is implementation specific
and your method might not work on all architectures. Even if the
driver is only meant to run on a single CPU architecture, it's
always better to write portable code.

	Arnd