[PATCH 1/2] clk: Do not complain about correctly set read-only muxes when assigning clock parents from device tree

[Philipp Zabel]

Assigning a clock parent to a mux with the CLK_MUX_READ_ONLY flag causes an
error "clk: failed to reparent read_only_mux to already_set_parent: -38"
even if the hardware is already set to the correct parent clock.

This patch avoids the error message by checking whether the correct parent
is already set before calling clk_set_parent. This allows to use the
assigned-clock-parents device tree binding for clock muxes that are not
allowed to be changed anymore at the time of_clk_set_defaults is called.

Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
 drivers/clk/clk-conf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/clk-conf.c b/drivers/clk/clk-conf.c
index aad4796..ca8dc86 100644
--- a/drivers/clk/clk-conf.c
+++ b/drivers/clk/clk-conf.c
@@ -62,7 +62,8 @@ static int __set_clk_parents(struct device_node *node, bool clk_supplier)
 			goto err;
 		}
 
-		rc = clk_set_parent(clk, pclk);
+		if (pclk != __clk_get_parent(clk))
+			rc = clk_set_parent(clk, pclk);
 		if (rc < 0)
 			pr_err("clk: failed to reparent %s to %s: %d\n",
 			       __clk_get_name(clk), __clk_get_name(pclk), rc);
-- 
2.1.3