lkml.org 
[lkml]   [2017]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 08/10] clk: fix CLK_SET_RATE_GATE with clock rate protection
Date
Using clock rate protection, we can now enforce CLK_SET_RATE_GATE along the
clock tree

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
drivers/clk/clk.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index f6fe5e5595ca..1af843ae20ff 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -605,6 +605,9 @@ static void clk_core_unprepare(struct clk_core *core)
if (WARN_ON(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL))
return;

+ if (core->flags & CLK_SET_RATE_GATE)
+ clk_core_rate_unprotect(core);
+
if (--core->prepare_count > 0)
return;

@@ -679,6 +682,16 @@ static int clk_core_prepare(struct clk_core *core)

core->prepare_count++;

+ /*
+ * CLK_SET_RATE_GATE is a special case of clock protection
+ * Instead of a consumer claiming exclusive rate control, it is
+ * actually the provider which prevents any consumer from making any
+ * operation which could result in a rate change or rate glitch while
+ * the clock is prepared.
+ */
+ if (core->flags & CLK_SET_RATE_GATE)
+ clk_core_rate_protect(core);
+
return 0;
unprepare:
clk_core_unprepare(core->parent);
@@ -1780,9 +1793,6 @@ static int clk_core_set_rate_nolock(struct clk_core *core,
if (clk_core_rate_is_protected(core))
return -EBUSY;

- if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
- return -EBUSY;
-
/* calculate new rates and get the topmost changed clock */
top = clk_calc_new_rates(core, req_rate);
if (!top)
--
2.14.3
\
 
 \ /
  Last update: 2017-12-01 22:53    [W:0.101 / U:0.764 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site