If a driver calls clk_set_parent(clk, parent) and parent is the
current parent of clk we shouldn't fail in any case.
Unfortunately if clk is a read-only mux we return -ENOSYS
because we think we can't change the parent, except for in this
special case where we don't actually need to change the parent at
all. Return 0 in such a situation.
Cc: Philipp Zabel <p.za...@pengutronix.de>
Signed-off-by: Stephen Boyd <sb...@codeaurora.org>
---
Based on clk-next
drivers/clk/clk.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index b82714a84f5e..670c8c86ce9f 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1969,16 +1969,18 @@ static int clk_core_set_parent(struct clk_core *clk,
struct clk_core *parent)
if (!clk)
return 0;
- /* verify ops for for multi-parent clks */
- if ((clk->num_parents > 1) && (!clk->ops->set_parent))
- return -ENOSYS;
-
/* prevent racing with updates to the clock topology */
clk_prepare_lock();
if (clk->parent == parent)
goto out;
+ /* verify ops for for multi-parent clks */
+ if ((clk->num_parents > 1) && (!clk->ops->set_parent)) {
+ ret = -ENOSYS;
+ goto out;
+ }
+
/* check that we are allowed to re-parent if the clock is in use */
if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) {
ret = -EBUSY;
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
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