clk: bail out early when rate is already desired one

Return successfully from clk_set_rate() when the rate is already the
desired one. This prevents a failure in clk_set_rate() when the current
clock doesn't have a set_rate hook.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.barebox.org/20210607141256.24801-1-s.hauer@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 8b90f30486..ba726c342c 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -169,6 +169,9 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);
 
+	if (clk_get_rate(clk) == clk_round_rate(clk, rate))
+		return 0;
+
 	if (!clk->ops->set_rate)
 		return -ENOSYS;