1 files changed, 49 insertions, 3 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 95a6f5dff5cc..8a389e650032 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -637,6 +637,24 @@ static void clk_core_get_boundaries(struct clk_core *core,
 		*max_rate = min(*max_rate, clk_user->max_rate);
 }
 
+static bool clk_core_check_boundaries(struct clk_core *core,
+				      unsigned long min_rate,
+				      unsigned long max_rate)
+{
+	struct clk *user;
+
+	lockdep_assert_held(&prepare_lock);
+
+	if (min_rate > core->max_rate || max_rate < core->min_rate)
+		return false;
+
+	hlist_for_each_entry(user, &core->clks, clks_node)
+		if (min_rate > user->max_rate || max_rate < user->min_rate)
+			return false;
+
+	return true;
+}
+
 void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
 			   unsigned long max_rate)
 {
@@ -2306,6 +2324,11 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 	clk->min_rate = min;
 	clk->max_rate = max;
 
+	if (!clk_core_check_boundaries(clk->core, min, max)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	rate = clk_core_get_rate_nolock(clk->core);
 	if (rate < min || rate > max) {
 		/*
@@ -2334,6 +2357,7 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 		}
 	}
 
+out:
 	if (clk->exclusive_count)
 		clk_core_rate_protect(clk->core);
 
@@ -3279,6 +3303,19 @@ static void clk_core_reparent_orphans_nolock(void)
 			__clk_set_parent_after(orphan, parent, NULL);
 			__clk_recalc_accuracies(orphan);
 			__clk_recalc_rates(orphan, 0);
+
+			/*
+			 * __clk_init_parent() will set the initial req_rate to
+			 * 0 if the clock doesn't have clk_ops::recalc_rate and
+			 * is an orphan when it's registered.
+			 *
+			 * 'req_rate' is used by clk_set_rate_range() and
+			 * clk_put() to trigger a clk_set_rate() call whenever
+			 * the boundaries are modified. Let's make sure
+			 * 'req_rate' is set to something non-zero so that
+			 * clk_set_rate_range() doesn't drop the frequency.
+			 */
+			orphan->req_rate = orphan->rate;
 		}
 	}
 }
@@ -3300,6 +3337,14 @@ static int __clk_core_init(struct clk_core *core)
 
 	clk_prepare_lock();
 
+	/*
+	 * Set hw->core after grabbing the prepare_lock to synchronize with
+	 * callers of clk_core_fill_parent_index() where we treat hw->core
+	 * being NULL as the clk not being registered yet. This is crucial so
+	 * that clks aren't parented until their parent is fully registered.
+	 */
+	core->hw->core = core;
+
 	ret = clk_pm_runtime_get(core);
 	if (ret)
 		goto unlock;
@@ -3453,8 +3498,10 @@ static int __clk_core_init(struct clk_core *core)
 out:
 	clk_pm_runtime_put(core);
 unlock:
-	if (ret)
+	if (ret) {
 		hlist_del_init(&core->child_node);
+		core->hw->core = NULL;
+	}
 
 	clk_prepare_unlock();
 
@@ -3700,7 +3747,6 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 	core->num_parents = init->num_parents;
 	core->min_rate = 0;
 	core->max_rate = ULONG_MAX;
-	hw->core = core;
 
 	ret = clk_core_populate_parent_map(core, init);
 	if (ret)
@@ -3718,7 +3764,7 @@ __clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
 		goto fail_create_clk;
 	}
 
-	clk_core_link_consumer(hw->core, hw->clk);
+	clk_core_link_consumer(core, hw->clk);
 
 	ret = __clk_core_init(core);
 	if (!ret)