[U-Boot] [PATCH 2/2] env: Add back default action of get_char in env_get_char()

[Maxime Ripard <maxime.ripard@bootlin.com>]

On Wed, Feb 07, 2018 at 02:17:12PM -0800, York Sun wrote:
> Commit 8a3a7e2270b3 ("env: Pass additional parameters to the env
> lookup function") dropped the default action if driver doesn't have
> get_char() defined. This causes failure to get environmental
> variables from NOR flash. Add back this default action for now.
> 
> Signed-off-by: York Sun <york.sun@nxp.com>
> CC: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
> Limited test on LS1043ARDB.
> 
>  env/env.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/env/env.c b/env/env.c
> index edfb575..210bae2 100644
> --- a/env/env.c
> +++ b/env/env.c
> @@ -159,7 +159,7 @@ int env_get_char(int index)
>  		int ret;
>  
>  		if (!drv->get_char)
> -			continue;
> +			return *(uchar *)(gd->env_addr + index);

Thinking more about this, I think this would break the case where the
first environment in your list has no get_char method, but the second
might.

Would something like that work?

------------ 8< --------
diff --git a/env/env.c b/env/env.c
index 9a89832c1aaf..391c9c0df2f0 100644
--- a/env/env.c
+++ b/env/env.c
@@ -152,6 +152,7 @@ static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
 int env_get_char(int index)
 {
        struct env_driver *drv;
+       bool has_get_char = false;
        int prio;
 
        if (gd->env_valid == ENV_INVALID)
@@ -166,6 +167,7 @@ int env_get_char(int index)
                if (!env_has_inited(drv->location))
                        continue;
 
+               has_get_char = true;
                ret = drv->get_char(index);
                if (!ret)
                        return 0;
@@ -174,6 +176,9 @@ int env_get_char(int index)
                      drv->name, ret);
        }
 
+       if (!has_get_char)
+               return *(uchar *)(gd->env_addr + index);
+
        return -ENODEV;
 }
------ 8< -------

Thanks!
Maxime

-- 
Maxime Ripard, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com
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