Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux

Pull clk fix from Stephen Boyd:
 "A single fix for the clk framework that needed some more bake time in
  linux-next.

  The problem is that two clks being registered at the same time can
  lead to a busted clk tree if the parent isn't fully registered by the
  time the child finds the parent. We rejigger the place where we mark
  the parent as fully registered so that the child can't find the parent
  until things are proper"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: Don't parent clks until the parent is fully registered

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f467d63bbf1e..566ee2c78709 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -3418,6 +3418,14 @@ 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;
@@ -3582,8 +3590,10 @@ 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();
 
@@ -3847,7 +3857,6 @@ __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)
@@ -3865,7 +3874,7 @@ __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)