Hi Fabio,
On 05/06/2014 05:49 PM, Fabio Estevam wrote:
On Tue, May 6, 2014 at 12:36 PM, Fabio Estevam <festevam@xxxxxxxxx> wrote:
Indeed, if I revert:
commit e7489693b3a853ab6dfad52f7e6af553ae8d3f28
Author: Maxime COQUELIN <maxime.coquelin@xxxxxx>
Date: Wed Jan 29 17:24:08 2014 +0100
clk: divider: Optimize clk_divider_bestdiv loop
Currently, the for-loop used to try all the different dividers to find the
one that best fit tries all the values from 1 to max_div,
incrementing by one.
In case of power-of-two, or table based divider, the loop isn't optimal.
Instead of incrementing by one, this patch provides directly the
next divider.
Signed-off-by: Maxime Coquelin <maxime.coquelin@xxxxxx>
Signed-off-by: Mike Turquette <mturquette@xxxxxxxxxx>
Then the board does not hang.
Isn't the increment of i missing?
i is incremented in _next_div():
+static int _next_div(struct clk_divider *divider, int div)
+{
+ div++;
+
+ if (divider->flags & CLK_DIVIDER_POWER_OF_TWO)
+ return __roundup_pow_of_two(div);
+ if (divider->table)
+ return _round_up_table(divider->table, div);
+
+ return div;
+}
Could you tell me which kind of divider it is? pow2, table, linear?
--- a/drivers/clk/clk-divider.c
+++ b/drivers/clk/clk-divider.c
@@ -279,7 +279,7 @@ static int clk_divider_bestdiv(struct clk_hw *hw,
unsigned long rate,
*/
maxdiv = min(ULONG_MAX / rate, maxdiv);
- for (i = 1; i <= maxdiv; i = _next_div(divider, i)) {
+ for (i = 1; i <= maxdiv; i +=_next_div(divider, i)) {
This would break power-of-two, and table based dividers.
if (!_is_valid_div(divider, i))
continue;
if (rate * i == parent_rate_saved) {
Regards,
Maxime
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