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authorStephen Boyd2015-02-02 23:11:25 +0100
committerStephen Boyd2015-03-12 20:18:53 +0100
commitb61c43c09f5e2b9bf8f340034c5ef1db8c64efa5 (patch)
treeb0aae827b8dd71fc4c268b49e0a43af906f2cfb6 /drivers/clk/clk.c
parentclk: Add tracepoints for hardware operations (diff)
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clk: clk_set_parent() with current parent shouldn't fail
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. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Michael Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r--drivers/clk/clk.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 42064cec2364..3e10cdff284b 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2055,16 +2055,18 @@ 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;