Re: [PATCH v3] nvmem: u-boot-env: align endianness of crc32 values

[Rafał Miłecki]

On 2023-02-13 14:23, INAGAKI Hiroshi wrote:
> This patch fixes crc32 error on Big-Endianness system by conversion of
> calculated crc32 value.
>
> Little-Endianness system:
>
>   obtained crc32: Little
> calculated crc32: Little
>
> Big-Endianness system:
>
>   obtained crc32: Little
> calculated crc32: Big
>
> log (APRESIA ApresiaLightGS120GT-SS, RTL8382M, Big-Endianness):
>
> [    8.570000] u_boot_env
> 18001200.spi:flash@0:partitions:partition@c0000: Invalid calculated
> CRC32: 0x88cd6f09 (expected: 0x096fcd88)
> [    8.580000] u_boot_env: probe of
> 18001200.spi:flash@0:partitions:partition@c0000 failed with error -22
>
> Fixes: f955dc144506 ("nvmem: add driver handling U-Boot environment 
> variables")
>
> Signed-off-by: INAGAKI Hiroshi <musashino.open@xxxxxxxxx>
> ---
> v2 -> v3
>
> - fix sparse warning by using __le32 type and cpu_to_le32
> - fix character length of the short commit hash in "Fixes:" tag
>
> v1 -> v2
>
> - wrong fix for sparse warning due to misunderstanding
> - add missing "Fixes:" tag
>
>  drivers/nvmem/u-boot-env.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/nvmem/u-boot-env.c b/drivers/nvmem/u-boot-env.c
> index 29b1d87a3c51..164bb04dfc3b 100644
> --- a/drivers/nvmem/u-boot-env.c
> +++ b/drivers/nvmem/u-boot-env.c
> @@ -117,8 +117,8 @@ static int u_boot_env_parse(struct u_boot_env 
> *priv)
>  	size_t crc32_offset;
>  	size_t data_offset;
>  	size_t data_len;
> -	uint32_t crc32;
> -	uint32_t calc;
> +	__le32 crc32;
> +	__le32 calc;
>  	size_t bytes;
>  	uint8_t *buf;
>  	int err;

This looks counter-intuitive to me, to store values on host system in
specified endianness. I'd say we should use __le32 type only to
represent numbers in device stored data (e.g. structs as processed by
device).

My suggesion: leave uint32_t for local variables and use le32_to_cpu().