From: Jerome Brunet <jbrunet@baylibre.com>
To: Stephen Boyd <sboyd@codeaurora.org>,
Michael Turquette <mturquette@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>,
linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org,
Russell King <linux@armlinux.org.uk>,
Linus Walleij <linus.walleij@linaro.org>,
Quentin Schulz <quentin.schulz@free-electrons.com>,
Kevin Hilman <khilman@baylibre.com>
Subject: [PATCH v4 08/10] clk: fix CLK_SET_RATE_GATE with clock rate protection
Date: Sun, 24 Sep 2017 22:00:28 +0200 [thread overview]
Message-ID: <20170924200030.6227-9-jbrunet@baylibre.com> (raw)
In-Reply-To: <20170924200030.6227-1-jbrunet@baylibre.com>
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>
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 4693d5e20327..f990ef127a83 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -552,6 +552,9 @@ 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;
@@ -622,6 +625,16 @@ 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;
}
@@ -1703,9 +1716,6 @@ 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)
--
2.13.5
next prev parent reply other threads:[~2017-09-24 20:01 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-24 20:00 [PATCH v4 00/10] clk: implement clock rate protection mechanism Jerome Brunet
2017-09-24 20:00 ` [PATCH v4 01/10] clk: fix incorrect usage of ENOSYS Jerome Brunet
2017-09-24 20:00 ` [PATCH v4 02/10] clk: take the prepare lock out of clk_core_set_parent Jerome Brunet
2017-09-24 20:00 ` [PATCH v4 03/10] clk: add clk_core_set_phase_nolock function Jerome Brunet
2017-09-24 20:00 ` [PATCH v4 04/10] clk: rework calls to round and determine rate callbacks Jerome Brunet
2017-09-24 20:00 ` [PATCH v4 05/10] clk: use round rate to bail out early in set_rate Jerome Brunet
2017-09-24 20:00 ` [PATCH v4 06/10] clk: add clock protection mechanism to clk core Jerome Brunet
2017-09-24 20:00 ` [PATCH v4 07/10] clk: cosmetic changes to clk_summary debugfs entry Jerome Brunet
2017-09-24 20:00 ` Jerome Brunet [this message]
2017-09-24 20:00 ` [PATCH v4 09/10] clk: add clk_rate_exclusive api Jerome Brunet
2017-10-26 5:26 ` Michael Turquette
2017-10-31 17:29 ` Jerome Brunet
2017-10-31 17:32 ` Michael Turquette
2017-09-24 20:00 ` [PATCH v4 10/10] clk: fix set_rate_range when current rate is out of range Jerome Brunet
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