1 files changed, 24 insertions, 18 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 687b00d67c8a..46317cbc088f 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -850,18 +850,21 @@ static void clk_change_rate(struct clk *clk)
 {
         struct clk *child;
         unsigned long old_rate;
+        unsigned long best_parent_rate = 0;
         struct hlist_node *tmp;
 
         old_rate = clk->rate;
 
+        if (clk->parent)
+                best_parent_rate = clk->parent->rate;
+
         if (clk->ops->set_rate)
-                clk->ops->set_rate(clk->hw, clk->new_rate, clk->parent->rate);
+                clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
 
         if (clk->ops->recalc_rate)
-                clk->rate = clk->ops->recalc_rate(clk->hw,
-                                clk->parent->rate);
+                clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate);
         else
-                clk->rate = clk->parent->rate;
+                clk->rate = best_parent_rate;
 
         if (clk->notifier_count && old_rate != clk->rate)
                 __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
@@ -999,7 +1002,7 @@ static struct clk *__clk_init_parent(struct clk *clk)
 
         if (!clk->parents)
                 clk->parents =
-                        kmalloc((sizeof(struct clk*) * clk->num_parents),
+                        kzalloc((sizeof(struct clk*) * clk->num_parents),
                                         GFP_KERNEL);
 
         if (!clk->parents)
@@ -1064,21 +1067,24 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent)
 
         old_parent = clk->parent;
 
-        /* find index of new parent clock using cached parent ptrs */
-        for (i = 0; i < clk->num_parents; i++)
-                if (clk->parents[i] == parent)
-                        break;
+        if (!clk->parents)
+                clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents),
+                                                                GFP_KERNEL);
 
         /*
-         * find index of new parent clock using string name comparison
-         * also try to cache the parent to avoid future calls to __clk_lookup
+         * find index of new parent clock using cached parent ptrs,
+         * or if not yet cached, use string name comparison and cache
+         * them now to avoid future calls to __clk_lookup.
          */
-        if (i == clk->num_parents)
-                for (i = 0; i < clk->num_parents; i++)
-                        if (!strcmp(clk->parent_names[i], parent->name)) {
+        for (i = 0; i < clk->num_parents; i++) {
+                if (clk->parents && clk->parents[i] == parent)
+                        break;
+                else if (!strcmp(clk->parent_names[i], parent->name)) {
+                        if (clk->parents)
                                 clk->parents[i] = __clk_lookup(parent->name);
-                                break;
-                        }
+                        break;
+                }
+        }
 
         if (i == clk->num_parents) {
                 pr_debug("%s: clock %s is not a possible parent of clock %s\n",
@@ -1229,8 +1235,8 @@ int __clk_init(struct device *dev, struct clk *clk)
          * If clk->parents is not NULL we skip this entire block.  This allows
          * for clock drivers to statically initialize clk->parents.
          */
-        if (clk->num_parents && !clk->parents) {
-                clk->parents = kmalloc((sizeof(struct clk*) * clk->num_parents),
+        if (clk->num_parents > 1 && !clk->parents) {
+                clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents),
                                 GFP_KERNEL);
                 /*
                  * __clk_lookup returns NULL for parents that have not been