Searched hist:da321133b53caf7889ed3ca1dabe4cc368db2604 (Results 1 – 1 of 1) sorted by relevance
/openbmc/linux/drivers/clk/ |
H A D | clk-divider.c | diff da321133b53caf7889ed3ca1dabe4cc368db2604 Sat Feb 21 04:40:23 CST 2015 Uwe Kleine-König <u.kleine-koenig@pengutronix.de> clk: divider: fix calculation of maximal parent rate for a given divider
The rate provided at the output of a clk-divider is calculated as:
DIV_ROUND_UP(parent_rate, div)
since commit b11d282dbea2 (clk: divider: fix rate calculation for fractional rates). So to yield a rate not bigger than r parent_rate must be <= r * div.
The effect of choosing a parent rate that is too big as was done before this patch results in wrongly ruling out good dividers.
Note that this is not a complete fix as __clk_round_rate might return a value >= its 2nd parameter. Also for dividers with CLK_DIVIDER_ROUND_CLOSEST set the calculation is not accurate. But this fixes the test case by Sascha Hauer that uses a chain of three dividers under a fixed clock.
Fixes: b11d282dbea2 (clk: divider: fix rate calculation for fractional rates) Suggested-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Michael Turquette <mturquette@linaro.org>
|