Messages in this thread | | | Date | Wed, 6 Nov 2013 11:15:34 +0000 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH] clk: divider: fix rate calculation for fractional rates |
| |
On Wed, Nov 06, 2013 at 01:06:48PM +0200, Tomi Valkeinen wrote: > This means that the following code works a bit oddly: > > rate = clk_round_rate(clk, 123428572); > clk_set_rate(clk, rate);
You're right, but the above sequence is quite a crass thing to do. Why?
clk_round_rate() returns the clock rate that clk_set_rate() would give you if you were to use this sequence:
clk_rate_rate(clk, 123428572); rate = clk_get_rate(clk);
The difference is that it doesn't change the actual clock rate itself; clk_round_rate() is meant to answer the question:
"If I were to set _this_ rate, what clock rate would the clock give me?"
thereby providing a method for drivers to inquire what the effect would be when changing such a clock without actually affecting it.
So please, don't use clk_round_rate() followed by clk_set_rate().
| |