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clk: at91: clk-generated: remove useless divisor loop 

The driver requests the current clk rate of each of its parent clocks to
decide whether a clock rate is suitable or not. It does not request
determine_rate from a parent clock which could request a rate change in
parent clock (i.e. there is no parent rate propagation).

We know the rate we want (passed along req argument of the function) and
the parent clock rate, thus we know the closest rounded divisor, we
don't need to iterate over the available divisors to find the best one
for a given clock.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
hifive-unleashed-5.1
Quentin Schulz 2017-08-10 08:34:01 +02:00 committed by Stephen Boyd
parent 8bb48f79ea
commit 8c7aa63289
1 changed files with 11 additions and 12 deletions
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23
drivers/clk/at91/clk-generated.c
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@ -124,19 +124,18 @@ static int clk_generated_determine_rate(struct clk_hw *hw,
(gck->range.max && min_rate > gck->range.max))
continue;
for (div = 1; div < GENERATED_MAX_DIV + 2; div++) {
tmp_rate = DIV_ROUND_CLOSEST(parent_rate, div);
tmp_diff = abs(req->rate - tmp_rate);
div = DIV_ROUND_CLOSEST(parent_rate, req->rate);
if (!div)
tmp_rate = parent_rate;
else
tmp_rate = parent_rate / div;
tmp_diff = abs(req->rate - tmp_rate);
if (best_diff < 0 || best_diff > tmp_diff) {
best_rate = tmp_rate;
best_diff = tmp_diff;
req->best_parent_rate = parent_rate;
req->best_parent_hw = parent;
}
if (!best_diff || tmp_rate < req->rate)
break;
if (best_diff < 0 || best_diff > tmp_diff) {
best_rate = tmp_rate;
best_diff = tmp_diff;
req->best_parent_rate = parent_rate;
req->best_parent_hw = parent;
}
if (!best_diff)