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Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/clk.c67
1 files changed, 52 insertions, 15 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index c83e8e543bab..de6b459de78e 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1363,31 +1363,71 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index)
unsigned long flags;
int ret = 0;
struct clk *old_parent = clk->parent;
+ bool migrated_enable = false;
- /* migrate prepare and enable */
+ /* migrate prepare */
if (clk->prepare_count)
__clk_prepare(parent);
- /* FIXME replace with clk_is_enabled(clk) someday */
flags = clk_enable_lock();
- if (clk->enable_count)
+
+ /* migrate enable */
+ if (clk->enable_count) {
__clk_enable(parent);
+ migrated_enable = true;
+ }
+
+ /* update the clk tree topology */
+ clk_reparent(clk, parent);
+
clk_enable_unlock(flags);
/* change clock input source */
if (parent && clk->ops->set_parent)
ret = clk->ops->set_parent(clk->hw, p_index);
- /* clean up old prepare and enable */
- flags = clk_enable_lock();
- if (clk->enable_count)
+ if (ret) {
+ /*
+ * The error handling is tricky due to that we need to release
+ * the spinlock while issuing the .set_parent callback. This
+ * means the new parent might have been enabled/disabled in
+ * between, which must be considered when doing rollback.
+ */
+ flags = clk_enable_lock();
+
+ clk_reparent(clk, old_parent);
+
+ if (migrated_enable && clk->enable_count) {
+ __clk_disable(parent);
+ } else if (migrated_enable && (clk->enable_count == 0)) {
+ __clk_disable(old_parent);
+ } else if (!migrated_enable && clk->enable_count) {
+ __clk_disable(parent);
+ __clk_enable(old_parent);
+ }
+
+ clk_enable_unlock(flags);
+
+ if (clk->prepare_count)
+ __clk_unprepare(parent);
+
+ return ret;
+ }
+
+ /* clean up enable for old parent if migration was done */
+ if (migrated_enable) {
+ flags = clk_enable_lock();
__clk_disable(old_parent);
- clk_enable_unlock(flags);
+ clk_enable_unlock(flags);
+ }
+ /* clean up prepare for old parent if migration was done */
if (clk->prepare_count)
__clk_unprepare(old_parent);
- return ret;
+ /* update debugfs with new clk tree topology */
+ clk_debug_reparent(clk, parent);
+ return 0;
}
/**
@@ -1450,14 +1490,11 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
/* do the re-parent */
ret = __clk_set_parent(clk, parent, p_index);
- /* propagate ABORT_RATE_CHANGE if .set_parent failed */
- if (ret) {
+ /* propagate rate recalculation accordingly */
+ if (ret)
__clk_recalc_rates(clk, ABORT_RATE_CHANGE);
- goto out;
- }
-
- /* propagate rate recalculation downstream */
- __clk_reparent(clk, parent);
+ else
+ __clk_recalc_rates(clk, POST_RATE_CHANGE);
out:
clk_prepare_unlock();