@@ -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.
*/
Remove old and misleading documentation from the previous clk_set_rate implementaion. Reported-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mike Turquette <mturquette@linaro.org> Cc: Arnd Bergman <arnd.bergmann@linaro.org> Cc: Olof Johansson <olof@lixom.net> Cc: Russell King <linux@arm.linux.org.uk> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Shawn Guo <shawn.guo@freescale.com> Cc: Richard Zhao <richard.zhao@linaro.org> Cc: Saravana Kannan <skannan@codeaurora.org> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Rajendra Nayak <rnayak@ti.com> Cc: Viresh Kumar <viresh.kumar@st.com> --- drivers/clk/clk.c | 41 +++++++++++------------------------------ 1 files changed, 11 insertions(+), 30 deletions(-)