linux-kernel - [PATCH 01/13] clk: core: correct clk_set

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Message-ID: <1334192572-12499-2-git-send-email-mturquette@linaro.org>
Date:	Wed, 11 Apr 2012 18:02:39 -0700
From:	Mike Turquette <mturquette@...aro.org>
To:	<arnd.bergmann@...aro.org>
CC:	<linux-kernel@...r.kernel.org>,
	<linux-arm-kernel@...ts.infradead.org>,
	<linaro-dev@...ts.linaro.org>, <patches@...aro.org>,
	Mike Turquette <mturquette@...aro.org>,
	Olof Johansson <olof@...om.net>,
	Russell King <linux@....linux.org.uk>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Shawn Guo <shawn.guo@...escale.com>,
	Richard Zhao <richard.zhao@...aro.org>,
	Saravana Kannan <skannan@...eaurora.org>,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Andrew Lunn <andrew@...n.ch>, Rajendra Nayak <rnayak@...com>,
	Viresh Kumar <viresh.kumar@...com>
Subject: [PATCH 01/13] clk: core: correct clk_set_rate kerneldoc

Remove old and misleading documentation from the previous clk_set_rate
implementaion.

Reported-by: Shawn Guo <shawn.guo@...aro.org>
Signed-off-by: Mike Turquette <mturquette@...aro.org>
Cc: Arnd Bergman <arnd.bergmann@...aro.org>
Cc: Olof Johansson <olof@...om.net>
Cc: Russell King <linux@....linux.org.uk>
Cc: Sascha Hauer <s.hauer@...gutronix.de>
Cc: Shawn Guo <shawn.guo@...escale.com>
Cc: Richard Zhao <richard.zhao@...aro.org>
Cc: Saravana Kannan <skannan@...eaurora.org>
Cc: Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc: Andrew Lunn <andrew@...n.ch>
Cc: Rajendra Nayak <rnayak@...com>
Cc: Viresh Kumar <viresh.kumar@...com>
---
 drivers/clk/clk.c |   41 +++++++++++------------------------------
 1 files changed, 11 insertions(+), 30 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 9cf6f59..3ed36d3 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.
  */
-- 
1.7.5.4

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