[U-Boot] [PATCH 1/2] env: common: Return specific error code on bad CRC

[Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>]

Am 18.01.2019 um 20:19 schrieb Sam Protsenko:
> Callers of env_import*() functions might want to check the case when we
> have incorrect environment (with bad CRC). For example, when environment
> location is being defined in env_load(), call chain may look like this:
> 
>      env_load() -> drv->load() = env_mmc_load() -> env_import()
> 
> Return code will be passed from env_import() all way up to env_load().
> Right now both env_mmc_load() and env_import() return -EIO error code,
> so env_load() can't differentiate between two cases:
>    1. Driver reports the error, because device is not accessible
>    2. Device is actually accessible, but environment is broken
> 
> Let's return -ENOMSG in env_import(), so we can distinguish two cases
> mentioned above. It will make it possible to continue working with "bad
> CRC" environment (like doing "env save"), instead of considering it not
> functional (implemented in subsequent patch).
> 
> Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>

Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>

> ---
>   env/common.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/env/common.c b/env/common.c
> index d1a6a52860..324502ed82 100644
> --- a/env/common.c
> +++ b/env/common.c
> @@ -115,7 +115,7 @@ int env_import(const char *buf, int check)
>   
>   		if (crc32(0, ep->data, ENV_SIZE) != crc) {
>   			set_default_env("bad CRC", 0);
> -			return -EIO;
> +			return -ENOMSG; /* needed for env_load() */
>   		}
>   	}
>   
> @@ -169,7 +169,7 @@ int env_import_redund(const char *buf1, int buf1_read_fail,
>   
>   	if (!crc1_ok && !crc2_ok) {
>   		set_default_env("bad CRC", 0);
> -		return -EIO;
> +		return -ENOMSG; /* needed for env_load() */
>   	} else if (crc1_ok && !crc2_ok) {
>   		gd->env_valid = ENV_VALID;
>   	} else if (!crc1_ok && crc2_ok) {
>