[RFC PATCH] clk: move check of CLK_SET_RATE_GATE flag to clk_propagate_rate_change()

From: jiada_wang
Date: Mon Jul 11 2016 - 00:56:13 EST

From: Jiada Wang <jiada_wang@xxxxxxxxxx>

Previously CLK_SET_RATE_GATE flag is only checked in clk_set_rate()
which only ensures the clock being called by clk_set_rate() won't
change rate when it has been prepared if CLK_SET_RATE_GATE flag is set.
But a clk_set_rate() request may propagate rate change to these clocks
from the requested clock's topmost parent clock to all its offsprings,
when any one of these clocks has CLK_SET_RATE_GATE flag set
and it has been prepared, the clk_set_rate() request should fail.

This patch moves check of CLK_SET_RATE_GATE flag to
clk_propagate_rate_change() to ensure all affected clocks will
be checked if their rate will be changed after clk_set_rate().

Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
drivers/clk/clk.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 820a939..aa5e4c3 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1437,6 +1437,9 @@ static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
if (core->rate == core->new_rate)
return NULL;

+ if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
+ return -EBUSY;
if (core->notifier_count) {
ret = __clk_notify(core, event, core->rate, core->new_rate);
@@ -1571,9 +1574,6 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
if (rate == clk_core_get_rate_nolock(core))
return 0;

- if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
- return -EBUSY;
/* calculate new rates and get the topmost changed clock */
top = clk_calc_new_rates(core, rate);
if (!top)