diff options
| author | Mike Turquette <mturquette@linaro.org> | 2012-05-03 01:23:43 +0200 |
|---|---|---|
| committer | Mike Turquette <mturquette@linaro.org> | 2012-05-08 23:11:53 +0200 |
| commit | 63f5c3b2b18dcaca0fc8983b52a3f5d4d70a0590 (patch) | |
| tree | 966cda40bacfc4be9dfc7c3b13427d7661665c2e /drivers/clk/clk.c | |
| parent | MAINTAINERS: add entry for common clk framework (diff) | |
| download | linux-63f5c3b2b18dcaca0fc8983b52a3f5d4d70a0590.tar.xz linux-63f5c3b2b18dcaca0fc8983b52a3f5d4d70a0590.zip | |
clk: prevent spurious parent rate propagation
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 <mturquette@linaro.org>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers/clk/clk.c')
| -rw-r--r-- | 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 8149764f8438..7ceca0e8645a 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) { |