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authorMaxime Ripard2022-03-25 17:11:44 +0100
committerStephen Boyd2022-03-25 16:55:51 -0700
commit7dabfa2bc4803eed83d6f22bd6f045495f40636b (patch)
tree77beb2b4bb80e5a13d5f9a6f6d6f1c4f98174f05 /drivers/clk
parent481f541ced8fcf9af87bedf6f87c2023de22bf6e (diff)
clk: Drop the rate range on clk_put()
When clk_put() is called we don't make another clk_set_rate() call to re-evaluate the rate boundaries. This is unlike clk_set_rate_range() that evaluates the rate again each time it is called. However, clk_put() is essentially equivalent to clk_set_rate_range() since after clk_put() completes the consumer's boundaries shouldn't be enforced anymore. Let's add a call to clk_set_rate_range() in clk_put() to make sure those rate boundaries are dropped and the clock provider drivers can react. Also add a few tests to make sure this case is covered. Fixes: c80ac50cbb37 ("clk: Always set the rate on clk_set_range_rate") Signed-off-by: Maxime Ripard <maxime@cerno.tech> Link: https://lore.kernel.org/r/20220325161144.1901695-4-maxime@cerno.tech [sboyd@kernel.org: Reword commit text] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/clk.c42
-rw-r--r--drivers/clk/clk_test.c108
2 files changed, 136 insertions, 14 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ad1595c13c9f..32a9eaf35c6b 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2332,19 +2332,15 @@ int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
}
EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
-/**
- * clk_set_rate_range - set a rate range for a clock source
- * @clk: clock source
- * @min: desired minimum clock rate in Hz, inclusive
- * @max: desired maximum clock rate in Hz, inclusive
- *
- * Returns success (0) or negative errno.
- */
-int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
+static int clk_set_rate_range_nolock(struct clk *clk,
+ unsigned long min,
+ unsigned long max)
{
int ret = 0;
unsigned long old_min, old_max, rate;
+ lockdep_assert_held(&prepare_lock);
+
if (!clk)
return 0;
@@ -2357,8 +2353,6 @@ int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
return -EINVAL;
}
- clk_prepare_lock();
-
if (clk->exclusive_count)
clk_core_rate_unprotect(clk->core);
@@ -2402,6 +2396,28 @@ out:
if (clk->exclusive_count)
clk_core_rate_protect(clk->core);
+ return ret;
+}
+
+/**
+ * clk_set_rate_range - set a rate range for a clock source
+ * @clk: clock source
+ * @min: desired minimum clock rate in Hz, inclusive
+ * @max: desired maximum clock rate in Hz, inclusive
+ *
+ * Return: 0 for success or negative errno on failure.
+ */
+int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
+{
+ int ret;
+
+ if (!clk)
+ return 0;
+
+ clk_prepare_lock();
+
+ ret = clk_set_rate_range_nolock(clk, min, max);
+
clk_prepare_unlock();
return ret;
@@ -4403,9 +4419,7 @@ void __clk_put(struct clk *clk)
}
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);
+ clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
owner = clk->core->owner;
kref_put(&clk->core->ref, __clk_release);
diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c
index 6731a822f4e3..fd2339cc5898 100644
--- a/drivers/clk/clk_test.c
+++ b/drivers/clk/clk_test.c
@@ -760,9 +760,65 @@ static void clk_range_test_multiple_set_range_rate_maximized(struct kunit *test)
clk_put(user1);
}
+/*
+ * Test that if we have several subsequent calls to
+ * clk_set_rate_range(), across multiple users, the core will reevaluate
+ * whether a new rate is needed, including when a user drop its clock.
+ *
+ * With clk_dummy_maximize_rate_ops, this means that the rate will
+ * trail along the maximum as it evolves.
+ */
+static void clk_range_test_multiple_set_range_rate_put_maximized(struct kunit *test)
+{
+ struct clk_dummy_context *ctx = test->priv;
+ struct clk_hw *hw = &ctx->hw;
+ struct clk *clk = hw->clk;
+ struct clk *user1, *user2;
+ unsigned long rate;
+
+ user1 = clk_hw_get_clk(hw, NULL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user1);
+
+ user2 = clk_hw_get_clk(hw, NULL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user2);
+
+ KUNIT_ASSERT_EQ(test,
+ clk_set_rate(clk, DUMMY_CLOCK_RATE_2 + 1000),
+ 0);
+
+ KUNIT_ASSERT_EQ(test,
+ clk_set_rate_range(user1,
+ 0,
+ DUMMY_CLOCK_RATE_2),
+ 0);
+
+ rate = clk_get_rate(clk);
+ KUNIT_ASSERT_GT(test, rate, 0);
+ KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2);
+
+ KUNIT_ASSERT_EQ(test,
+ clk_set_rate_range(user2,
+ 0,
+ DUMMY_CLOCK_RATE_1),
+ 0);
+
+ rate = clk_get_rate(clk);
+ KUNIT_ASSERT_GT(test, rate, 0);
+ KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
+
+ clk_put(user2);
+
+ rate = clk_get_rate(clk);
+ KUNIT_ASSERT_GT(test, rate, 0);
+ KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2);
+
+ clk_put(user1);
+}
+
static struct kunit_case clk_range_maximize_test_cases[] = {
KUNIT_CASE(clk_range_test_set_range_rate_maximized),
KUNIT_CASE(clk_range_test_multiple_set_range_rate_maximized),
+ KUNIT_CASE(clk_range_test_multiple_set_range_rate_put_maximized),
{}
};
@@ -877,9 +933,61 @@ static void clk_range_test_multiple_set_range_rate_minimized(struct kunit *test)
clk_put(user1);
}
+/*
+ * Test that if we have several subsequent calls to
+ * clk_set_rate_range(), across multiple users, the core will reevaluate
+ * whether a new rate is needed, including when a user drop its clock.
+ *
+ * With clk_dummy_minimize_rate_ops, this means that the rate will
+ * trail along the minimum as it evolves.
+ */
+static void clk_range_test_multiple_set_range_rate_put_minimized(struct kunit *test)
+{
+ struct clk_dummy_context *ctx = test->priv;
+ struct clk_hw *hw = &ctx->hw;
+ struct clk *clk = hw->clk;
+ struct clk *user1, *user2;
+ unsigned long rate;
+
+ user1 = clk_hw_get_clk(hw, NULL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user1);
+
+ user2 = clk_hw_get_clk(hw, NULL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, user2);
+
+ KUNIT_ASSERT_EQ(test,
+ clk_set_rate_range(user1,
+ DUMMY_CLOCK_RATE_1,
+ ULONG_MAX),
+ 0);
+
+ rate = clk_get_rate(clk);
+ KUNIT_ASSERT_GT(test, rate, 0);
+ KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
+
+ KUNIT_ASSERT_EQ(test,
+ clk_set_rate_range(user2,
+ DUMMY_CLOCK_RATE_2,
+ ULONG_MAX),
+ 0);
+
+ rate = clk_get_rate(clk);
+ KUNIT_ASSERT_GT(test, rate, 0);
+ KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_2);
+
+ clk_put(user2);
+
+ rate = clk_get_rate(clk);
+ KUNIT_ASSERT_GT(test, rate, 0);
+ KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
+
+ clk_put(user1);
+}
+
static struct kunit_case clk_range_minimize_test_cases[] = {
KUNIT_CASE(clk_range_test_set_range_rate_minimized),
KUNIT_CASE(clk_range_test_multiple_set_range_rate_minimized),
+ KUNIT_CASE(clk_range_test_multiple_set_range_rate_put_minimized),
{}
};