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 544c9564c621d515ccea84e9dd5477f0a6f411d0..f66af1ccdb9f13ff6c735d35e98f95dd5f04bd13 100644 (file)
--- 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);