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From: mturquette@linaro.org (Mike Turquette)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 01/13] clk: core: correct clk_set_rate kerneldoc
Date: Wed, 11 Apr 2012 18:02:39 -0700	[thread overview]
Message-ID: <1334192572-12499-2-git-send-email-mturquette@linaro.org> (raw)
In-Reply-To: <1334192572-12499-1-git-send-email-mturquette@linaro.org>

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(-)

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

  reply	other threads:[~2012-04-12  1:02 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-12  1:02 [PATCH 00/13] common clk framework misc fixes Mike Turquette
2012-04-12  1:02 ` Mike Turquette [this message]
2012-04-12  4:28   ` [PATCH 01/13] clk: core: correct clk_set_rate kerneldoc Viresh Kumar
2012-04-13 22:23     ` Turquette, Mike
2012-04-12  7:24   ` Andrew Lunn
2012-04-12  7:38     ` Amit Kucheria
2012-04-12  1:02 ` [PATCH 02/13] clk: core: remove dead code paths Mike Turquette
2012-04-12  6:14   ` Viresh Kumar
2012-04-13 22:27     ` Turquette, Mike
2012-04-12  1:02 ` [PATCH 03/13] clk: core: clk_calc_new_rates handles NULL parents Mike Turquette
2012-04-12  1:02 ` [PATCH 04/13] clk: core: enforce clk_ops consistency Mike Turquette
2012-04-12  6:17   ` Viresh Kumar
2012-04-12  1:02 ` [PATCH 05/13] clk: use kzalloc in clk_register_mux Mike Turquette
2012-04-12  6:18   ` Viresh Kumar
2012-04-12  1:02 ` [PATCH 06/13] clk: remove unnecessary EXPORT_SYMBOL_GPL Mike Turquette
2012-04-12  6:18   ` Viresh Kumar
2012-04-12  1:02 ` [PATCH 07/13] clk: add "const" for clk_ops of basic clks Mike Turquette
2012-04-12  6:19   ` Viresh Kumar
2012-04-12  1:02 ` [PATCH 08/13] clk: declare clk_ops of basic clks in clk-provider.h Mike Turquette
2012-04-12  6:20   ` Viresh Kumar
2012-04-12  1:02 ` [PATCH 09/13] clk: Make clk_get_rate() return 0 on error Mike Turquette
2012-04-12  6:21   ` Viresh Kumar
2012-04-12  1:02 ` [PATCH 10/13] clk: Remove comment for end of CONFIG_COMMON_CLK section Mike Turquette
2012-04-12  1:02 ` [PATCH 11/13] clk: Constify parent name arrays Mike Turquette
2012-04-12  1:02 ` [PATCH 12/13] clk: core: copy parent_names & return error codes Mike Turquette
2012-04-16 20:30   ` Sascha Hauer
2012-04-16 21:35     ` Turquette, Mike
2012-04-12  1:02 ` [PATCH 13/13] clk: basic: improve parent_names & return errors Mike Turquette
2012-04-12  6:49   ` Shawn Guo
2012-04-16 23:10     ` Turquette, Mike
2012-04-17  1:46       ` Shawn Guo
2012-04-17  3:50         ` Turquette, Mike
2012-04-17  7:17           ` Shawn Guo
2012-04-20 20:01             ` Saravana Kannan
2012-04-26  6:00             ` Saravana Kannan
2012-04-16 20:52   ` Sascha Hauer
2012-04-16 23:11     ` Turquette, Mike
2012-04-12  8:56 ` [PATCH 00/13] common clk framework misc fixes Sascha Hauer
2012-04-12 11:14 ` Arnd Bergmann
2012-04-12 13:11   ` Shawn Guo
2012-04-12 12:50 ` [PATCH 1/3] clk: always pass parent_rate into .round_rate Shawn Guo
2012-04-12 12:50   ` [PATCH 2/3] clk: pass parent_rate into .set_rate Shawn Guo
2012-04-18  1:05     ` Turquette, Mike
2012-04-12 12:50   ` [PATCH 3/3] clk: propagate round_rate for CLK_SET_RATE_PARENT case Shawn Guo
2012-04-18  1:07     ` Turquette, Mike
2012-04-18  1:05   ` [PATCH 1/3] clk: always pass parent_rate into .round_rate Turquette, Mike
2012-05-02  9:51   ` Sascha Hauer
2012-05-06 23:41     ` Turquette, Mike
2012-04-13  9:21 ` [PATCH 00/13] common clk framework misc fixes Mark Brown
2012-04-13 22:20   ` Turquette, Mike

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