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clk: check ->determine/round_rate() return value in clk_calc_new_rates 

->determine_rate() and ->round_rate() can return the closest rate to the
requested one or an error code.
clk_calc_new_rates is assuming these functions can't return a negative
value, which leads to a undefined behavior when the clk implementation
returns such an error code.
Fix this by returning NULL in case ->determine_rate() or ->round_rate()
returned an error code.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
This commit is contained in:
Boris Brezillon 2015-03-29 03:48:48 +02:00 committed by Michael Turquette
parent 4591243102
commit 03bc10ab5b
1 changed files with 16 additions and 7 deletions
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23
drivers/clk/clk.c
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@ -1618,6 +1618,7 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
unsigned long min_rate;
unsigned long max_rate;
int p_index = 0;
long ret;
/* sanity */
if (IS_ERR_OR_NULL(clk))
@ -1633,15 +1634,23 @@ static struct clk_core *clk_calc_new_rates(struct clk_core *clk,
/* find the closest rate and parent clk/rate */
if (clk->ops->determine_rate) {
parent_hw = parent ? parent->hw : NULL;
new_rate = clk->ops->determine_rate(clk->hw, rate,
min_rate,
max_rate,
&best_parent_rate,
&parent_hw);
ret = clk->ops->determine_rate(clk->hw, rate,
min_rate,
max_rate,
&best_parent_rate,
&parent_hw);
if (ret < 0)
return NULL;
new_rate = ret;
parent = parent_hw ? parent_hw->core : NULL;
} else if (clk->ops->round_rate) {
new_rate = clk->ops->round_rate(clk->hw, rate,
&best_parent_rate);
ret = clk->ops->round_rate(clk->hw, rate,
&best_parent_rate);
if (ret < 0)
return NULL;
new_rate = ret;
if (new_rate < min_rate || new_rate > max_rate)
return NULL;
} else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) {