re-adding clocksource_get_next ?

[Giuseppe CAVALLARO <peppe.cavallaro@st.com>]

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Hello!
this function was removed in the past but I've not clear all the details.
While testing LLTng, I wrote the patch, in attachment, that re-adds it
again.
The clocksource_get_next returns the first clock source available
(without looking at the rating).
In my environment, a clock source is a TMU channel (e.g. TMU1) and,
indeed, clocksource_get_next works fine.

Let me know if it makes sense or if I'm missing something.

Best Regards,
Giuseppe

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>From d05e9a31e4d697b704a1d9170aeee7235ffffb0f Mon Sep 17 00:00:00 2001
From: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Date: Tue, 6 Apr 2010 16:04:46 +0200
Subject: [PATCH] add clocksource_get_next

Added the clocksource_get_next function, it returns a source clock.
The clocksource_get_next function has been used for testing LTT
and implementing trace clock definitions on ST platforms.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
---
 kernel/time/clocksource.c |   17 +++++++++++++++++
 1 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 0e98497..c9e8f56 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -613,6 +613,23 @@ static void clocksource_enqueue(struct clocksource *cs)
 	list_add(&cs->list, entry);
 }
 
+/*
+ * Return a clocksource if available
+ */
+struct clocksource *clocksource_get_next(void)
+{
+	struct clocksource *clock = NULL;
+
+	mutex_lock(&clocksource_mutex);
+	if (!list_empty(&clocksource_list)) {
+		struct list_head *list = clocksource_list.next;
+		clock = container_of(list, struct clocksource, list);
+	}
+	mutex_unlock(&clocksource_mutex);
+
+	return clock;
+}
+
 /**
  * clocksource_register - Used to install new clocksources
  * @t:		clocksource to be registered
-- 
1.6.0.4