UPSTREAM: clk: skip unnecessary set_phase if nothing to do

Let's compare the degrees from clk_set_rate with
clk->core->phase. If the requested degrees is already
there, skip the following steps.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[sboyd@codeaurora.org: s/drgrees/degrees/ in commit text]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
(cherry picked from git.kernel.org clk/linux.git clk-next
 commit 023bd7166be0595d18220dfd5c9765b3970f6ef3)

Change-Id: Icc3be314e8f696a18bf0cd92867cd5f956817bbc

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index bd64a9414de2684c2d329399f06cc885b832099e..544c9564c621d515ccea84e9dd5477f0a6f411d0 100644 (file)
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1902,6 +1902,10 @@ int clk_set_phase(struct clk *clk, int degrees)
 
        clk_prepare_lock();
 
+       /* bail early if nothing to do */
+       if (degrees == clk->core->phase)
+               goto out;
+
        trace_clk_set_phase(clk->core, degrees);
 
        if (clk->core->ops->set_phase)
@@ -1912,6 +1916,7 @@ int clk_set_phase(struct clk *clk, int degrees)
        if (!ret)
                clk->core->phase = degrees;
 
+out:
        clk_prepare_unlock();
 
        return ret;