clk: migrate ref counts when orphans are reunited

It's always nice to see families reunited, and this is equally true when
talking about parent clocks and their children. However, if the orphan
clk had a positive prepare_count or enable_count, then we would not
migrate those counts up the parent chain correctly.

This has manifested with the recent critical clocks feature, which often
enables clocks very early, before their parents have been registered.

Fixed by replacing the call to clk_core_reparent with calls to
__clk_set_parent_{before,after}.

Cc: James Liao <jamesjj.liao@mediatek.com>
Cc: Erin Lo <erin.lo@mediatek.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
[sboyd@codeaurora.org: Recalc accuracies and rates too]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 820a939fb6bb..238b989bf778 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2449,8 +2449,16 @@ static int __clk_core_init(struct clk_core *core)
 	hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
 		struct clk_core *parent = __clk_init_parent(orphan);
 
-		if (parent)
-			clk_core_reparent(orphan, parent);
+		/*
+		 * we could call __clk_set_parent, but that would result in a
+		 * redundant call to the .set_rate op, if it exists
+		 */
+		if (parent) {
+			__clk_set_parent_before(orphan, parent);
+			__clk_set_parent_after(orphan, parent, NULL);
+			__clk_recalc_accuracies(orphan);
+			__clk_recalc_rates(orphan, 0);
+		}
 	}
 
 	/*