[PATCH V3] env: Fix invalid env handling in env_init()

[Tim Harvey]

On Wed, Jan 20, 2021 at 6:45 AM Marek Vasut <marex at denx.de> wrote:
>
> This fixes the case where there are multiple environment drivers, one of
> them is the default environment one, and it is followed by an environment
> driver which does not implement .init() callback. The default environment
> driver sets gd->env_valid to ENV_INVALID and returns 0 from its .init()
> callback implementation, which is valid behavior for default environment.
>
> Since the subsequent environment driver does not implement .init(), it
> also does not modify the $ret variable in the loop. Therefore, the loop
> is exited with gd->env_valid=ENV_INVALID and ret=0, which means that the
> code further down in env_init() will not reset the environment to the
> default one, which is incorrect.
>
> This patch sets the $ret variable back to -ENOENT in case the env_valid
> is set to ENV_INVALID by an environment driver, so that the environment
> would be correctly reset back to default one, unless a subsequent driver
> loads a valid environment.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> V2: Reword commit message
> V3: Rebase
> ---
>  env/env.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/env/env.c b/env/env.c
> index 37b4b54cb75..7faa7ab661b 100644
> --- a/env/env.c
> +++ b/env/env.c
> @@ -334,6 +334,9 @@ int env_init(void)
>
>                 debug("%s: Environment %s init done (ret=%d)\n", __func__,
>                       drv->name, ret);
> +
> +               if (gd->env_valid == ENV_INVALID)
> +                       ret = -ENOENT;
>         }
>
>         if (!prio)
> --
> 2.29.2
>

Without this patch, multiple environments with MMC being one of them
fail to work as described in the commit message (becuase MMC does not
have an init callback). I verified this patch resolves the issue using
an IMX8M mini with CONFIG_ENV_IS_NOWHERE=y and CONFIG_ENV_IS_IN_MMC=y.

Tested-By: Tim Harvey <tharvey at gateworks.com>