u-boot: remove driver lookup loop from env_save()

When called with ENVOP_SAVE, env_get_location() only returns the
gd->env_load_location variable without actually checking for
the environment location and priority.

This behaviour causes env_save() to fall into an infinite loop when
the low-level drv->save() call fails.

The env_save() function should not loop through the environment
location list but it should save the environment into the location
stored in gd->env_load_location by the last env_load() call.

Signed-off-by: Nicholas Faustini <nicholas.faustini@azcomtech.com>
Reviewed-by: Simon Goldschmidt <sgoldschmidt@de.pepperl-fuchs.com>

diff --git a/env/env.c b/env/env.c
index 5c0842ac07eb2d728fef5f349ab0cd8d1b26dc73..e033b461244808b81df25aa0e02785e5f3c30463 100644 (file)
--- a/env/env.c
+++ b/env/env.c
@@ -119,21 +119,12 @@ static void env_set_inited(enum env_location location)
  */
 __weak enum env_location env_get_location(enum env_operation op, int prio)
 {
-       switch (op) {
-       case ENVOP_GET_CHAR:
-       case ENVOP_INIT:
-       case ENVOP_LOAD:
-               if (prio >= ARRAY_SIZE(env_locations))
-                       return ENVL_UNKNOWN;
-
-               gd->env_load_location = env_locations[prio];
-               return gd->env_load_location;
-
-       case ENVOP_SAVE:
-               return gd->env_load_location;
-       }
+       if (prio >= ARRAY_SIZE(env_locations))
+               return ENVL_UNKNOWN;
+
+       gd->env_load_prio = prio;
 
-       return ENVL_UNKNOWN;
+       return env_locations[prio];
 }
 
 
@@ -205,22 +196,29 @@ int env_load(void)
                        return 0;
        }
 
+       /*
+        * In case of invalid environment, we set the 'default' env location
+        * to the highest priority. In this way, next calls to env_save()
+        * will restore the environment at the right place.
+        */
+       env_get_location(ENVOP_LOAD, 0);
+
        return -ENODEV;
 }
 
 int env_save(void)
 {
        struct env_driver *drv;
-       int prio;
 
-       for (prio = 0; (drv = env_driver_lookup(ENVOP_SAVE, prio)); prio++) {
+       drv = env_driver_lookup(ENVOP_SAVE, gd->env_load_prio);
+       if (drv) {
                int ret;
 
                if (!drv->save)
-                       continue;
+                       return -ENODEV;
 
                if (!env_has_inited(drv->location))
-                       continue;
+                       return -ENODEV;
 
                printf("Saving Environment to %s... ", drv->name);
                ret = drv->save();

diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 0fd4900392be58b9da2be98461ac403a81aeb4e8..c83fc01b7646d49280456c11b19de2eade316a3e 100644 (file)
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -50,7 +50,7 @@ typedef struct global_data {
        unsigned long env_addr;         /* Address  of Environment struct */
        unsigned long env_valid;        /* Environment valid? enum env_valid */
        unsigned long env_has_init;     /* Bitmask of boolean of struct env_location offsets */
-       int env_load_location;
+       int env_load_prio;              /* Priority of the loaded environment */
 
        unsigned long ram_base;         /* Base address of RAM used by U-Boot */
        unsigned long ram_top;          /* Top address of RAM used by U-Boot */