From: Heiko Stuebner <heiko@sntech.de>
To: mturquette@baylibre.com, sboyd@codeaurora.org
Cc: linux-clk@vger.kernel.org, linux-rockchip@lists.infradead.org,
zhengxing@rock-chips.com, zhangqing@rock-chips.com,
tomeu.vizoso@collabora.com, Heiko Stuebner <heiko@sntech.de>
Subject: [RFC PATCH 1/3] clk: fix inconsistent use of req_rate
Date: Mon, 2 May 2016 18:36:20 +0200 [thread overview]
Message-ID: <1462206982-10444-2-git-send-email-heiko@sntech.de> (raw)
In-Reply-To: <1462206982-10444-1-git-send-email-heiko@sntech.de>
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.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
drivers/clk/clk.c | 24 ++++++++++++++++++------
1 file changed, 18 insertions(+), 6 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f079ea4..65e0aad 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1507,8 +1507,10 @@ 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;
@@ -1599,9 +1601,14 @@ 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();
@@ -2379,7 +2386,7 @@ static int __clk_core_init(struct clk_core *core)
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 newly finds a
@@ -2809,6 +2816,7 @@ 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)))
@@ -2817,9 +2825,13 @@ 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);
--
2.8.0.rc3
next prev parent reply other threads:[~2016-05-02 16:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-02 16:36 [RFC PATCH 0/3] clk: attempt to keep requested rate on parent changes Heiko Stuebner
2016-05-02 16:36 ` Heiko Stuebner [this message]
2016-05-02 16:36 ` [RFC PATCH 2/3] clk: adjust clocks to their requested rate after " Heiko Stuebner
2016-05-06 0:35 ` Doug Anderson
2016-05-06 0:49 ` Doug Anderson
2016-05-08 20:34 ` Heiko Stuebner
2016-05-09 11:40 ` Heiko Stuebner
2016-05-09 15:49 ` Doug Anderson
2016-07-05 7:27 ` Elaine Zhang
2016-07-05 22:24 ` Heiko Stuebner
2016-07-06 1:39 ` Elaine Zhang
2016-07-06 23:01 ` Doug Anderson
2016-07-06 22:41 ` Doug Anderson
2016-05-02 16:36 ` [RFC PATCH 3/3] clk: rockchip: make rk3399 vop dclks keep their rate on parent rate changes Heiko Stuebner
2016-05-05 13:30 ` [RFC PATCH 0/3] clk: attempt to keep requested rate on parent changes Tomeu Vizoso
2016-05-05 15:07 ` Heiko Stübner
2016-05-06 0:46 ` Doug Anderson
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