From 5654dc94f872f823aa13941a8fdba69a3feca39c Mon Sep 17 00:00:00 2001 From: Mike Turquette Date: Mon, 26 Mar 2012 11:51:34 -0700 Subject: clk: core: correct clk_set_rate kerneldoc Remove old and misleading documentation from the previous clk_set_rate implementaion. Reported-by: Shawn Guo Signed-off-by: Mike Turquette --- drivers/clk/clk.c | 41 +++++++++++------------------------------ 1 file changed, 11 insertions(+), 30 deletions(-) (limited to 'drivers/clk') diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 9cf6f59e3e1..3ed36d3056d 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -859,38 +859,19 @@ static void clk_change_rate(struct clk *clk) * @clk: the clk whose rate is being changed * @rate: the new rate for clk * - * In the simplest case clk_set_rate will only change the rate of clk. + * In the simplest case clk_set_rate will only adjust the rate of clk. * - * If clk has the CLK_SET_RATE_GATE flag set and it is enabled this call - * will fail; only when the clk is disabled will it be able to change - * its rate. + * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to + * propagate up to clk's parent; whether or not this happens depends on the + * outcome of clk's .round_rate implementation. If *parent_rate is unchanged + * after calling .round_rate then upstream parent propagation is ignored. If + * *parent_rate comes back with a new rate for clk's parent then we propagate + * up to clk's parent and set it's rate. Upward propagation will continue + * until either a clk does not support the CLK_SET_RATE_PARENT flag or + * .round_rate stops requesting changes to clk's parent_rate. * - * Setting the CLK_SET_RATE_PARENT flag allows clk_set_rate to - * recursively propagate up to clk's parent; whether or not this happens - * depends on the outcome of clk's .round_rate implementation. If - * *parent_rate is 0 after calling .round_rate then upstream parent - * propagation is ignored. If *parent_rate comes back with a new rate - * for clk's parent then we propagate up to clk's parent and set it's - * rate. Upward propagation will continue until either a clk does not - * support the CLK_SET_RATE_PARENT flag or .round_rate stops requesting - * changes to clk's parent_rate. If there is a failure during upstream - * propagation then clk_set_rate will unwind and restore each clk's rate - * that had been successfully changed. Afterwards a rate change abort - * notification will be propagated downstream, starting from the clk - * that failed. - * - * At the end of all of the rate setting, clk_set_rate internally calls - * __clk_recalc_rates and propagates the rate changes downstream, - * starting from the highest clk whose rate was changed. This has the - * added benefit of propagating post-rate change notifiers. - * - * Note that while post-rate change and rate change abort notifications - * are guaranteed to be sent to a clk only once per call to - * clk_set_rate, pre-change notifications will be sent for every clk - * whose rate is changed. Stacking pre-change notifications is noisy - * for the drivers subscribed to them, but this allows drivers to react - * to intermediate clk rate changes up until the point where the final - * rate is achieved at the end of upstream propagation. + * Rate changes are accomplished via tree traversal that also recalculates the + * rates for the clocks and fires off POST_RATE_CHANGE notifiers. * * Returns 0 on success, -EERROR otherwise. */ -- cgit v1.2.3-70-g09d2