Patch 'clk: always pass parent_rate into .round_rate' made a subtle
change to the semantics of .round_rate. It is now expected for the
parent's rate to always be passed in, simplifying the implemenation of
various .round_rate callback definitions.
However the patch also introduced a bug in clk_calc_new_rates whereby a
clock without the CLK_SET_RATE_PARENT flag set could still propagate a
rate change up to a parent clock if the the .round_rate callback
modified the &best_parent_rate value in any way.
This patch fixes the issue at the framework level (in
clk_calc_new_rates) by specifically handling the case where the
CLK_SET_RATE_PARENT flag is not set.
Signed-off-by: Mike Turquette <mturque...@linaro.org>
Reported-by: Sascha Hauer<s.ha...@pengutronix.de>
---
drivers/clk/clk.c | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 8149764..7ceca0e 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -774,12 +774,18 @@ static struct clk *clk_calc_new_rates(struct clk *clk,
unsigned long rate)
if (IS_ERR_OR_NULL(clk))
return NULL;
+ /* save parent rate, if it exists */
+ if (clk->parent)
+ best_parent_rate = clk->parent->rate;
+
/* never propagate up to the parent */
if (!(clk->flags & CLK_SET_RATE_PARENT)) {
if (!clk->ops->round_rate) {
clk->new_rate = clk->rate;
return NULL;
}
+ new_rate = clk->ops->round_rate(clk->hw, rate,
&best_parent_rate);
+ goto out;
}
/* need clk->parent from here on out */
@@ -795,7 +801,6 @@ static struct clk *clk_calc_new_rates(struct clk *clk,
unsigned long rate)
goto out;
}
- best_parent_rate = clk->parent->rate;
new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate);
if (best_parent_rate != clk->parent->rate) {
--
1.7.5.4
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