From: Heiko Stuebner <heiko@sntech.de>
Date: Mon, 2 May 2016 16:36:20 +0000 (+0200)
Subject: FROMLIST: clk: fix inconsistent use of req_rate
X-Git-Tag: firefly_0821_release~2666
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=dd7fe1d5e1b1d5d9c66246f51aad0fdd072d7401;p=firefly-linux-kernel-4.4.55.git

FROMLIST: clk: fix inconsistent use of req_rate

The req_rate property seems to be made to hold the rate requested through
clk_set_rate. Currently it gets initialized in clk_init to the clocks
current rate and then adapted in clk_set_rate calls. Orphan clocks and
their children get initialized to a rate of 0 and req_rate never gets
re-set when these lose their orphan-status.

Initializing req_rate to the clocks rate also is unintuitive as it just
copies the value that is already in the rate property and also looses the
information if a component actually requested a specific rate.

So separate the requested rate and only set it in clk_core_set_rate_nolock
when a real rate gets requested. The users of the req_rate __clk_put and
clk_set_rate_range that adjust a clock based on that value use req_rate
at first and fall back to rate if no rate had been requested now.

(am from https://patchwork.kernel.org/patch/8993751/)

Change-Id: I9e345e1e9d0c101d5c3c7064b6c2d2724f9eac4f
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Xing Zheng <zhengxing@rock-chips.com>
---

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 544c9564c621..f66af1ccdb9f 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1520,8 +1520,10 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
 		return 0;
 
 	/* bail early if nothing to do */
-	if (rate == clk_core_get_rate_nolock(core))
+	if (rate == clk_core_get_rate_nolock(core)) {
+		core->req_rate = req_rate;
 		return 0;
+	}
 
 	if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
 		return -EBUSY;
@@ -1612,9 +1614,14 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
 	clk_prepare_lock();
 
 	if (min != clk->min_rate || max != clk->max_rate) {
+		unsigned long rate = clk->core->req_rate;
+
+		if (!rate)
+			rate = clk->core->rate;
+
 		clk->min_rate = min;
 		clk->max_rate = max;
-		ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
+		ret = clk_core_set_rate_nolock(clk->core, rate);
 	}
 
 	clk_prepare_unlock();
@@ -2456,7 +2463,7 @@ static int __clk_init(struct device *dev, struct clk *clk_user)
 		rate = core->parent->rate;
 	else
 		rate = 0;
-	core->rate = core->req_rate = rate;
+	core->rate = rate;
 
 	/*
 	 * walk the list of orphan clocks and reparent any that are children of
@@ -2794,6 +2801,7 @@ int __clk_get(struct clk *clk)
 
 void __clk_put(struct clk *clk)
 {
+	unsigned long rate;
 	struct module *owner;
 
 	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
@@ -2802,9 +2810,13 @@ void __clk_put(struct clk *clk)
 	clk_prepare_lock();
 
 	hlist_del(&clk->clks_node);
-	if (clk->min_rate > clk->core->req_rate ||
-	    clk->max_rate < clk->core->req_rate)
-		clk_core_set_rate_nolock(clk->core, clk->core->req_rate);
+
+	rate = clk->core->req_rate;
+	if (!rate)
+		rate = clk->core->rate;
+
+	if (clk->min_rate > rate || clk->max_rate < rate)
+		clk_core_set_rate_nolock(clk->core, rate);
 
 	owner = clk->core->owner;
 	kref_put(&clk->core->ref, __clk_release);