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author | Maxime Ripard <maxime@cerno.tech> | 2022-08-16 13:25:07 +0200 |
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committer | Stephen Boyd <sboyd@kernel.org> | 2022-09-15 09:30:14 -0700 |
commit | d77388223240884b918b8d85f88f132916afbf06 (patch) | |
tree | f06be10e49817e849bf0c6381da2bcfac9a4cb6f /drivers | |
parent | aac00c7fa1149fd5b5a5110096ffa78dcb120b79 (diff) | |
download | linux-stable-d77388223240884b918b8d85f88f132916afbf06.tar.gz linux-stable-d77388223240884b918b8d85f88f132916afbf06.tar.bz2 linux-stable-d77388223240884b918b8d85f88f132916afbf06.zip |
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. In
order to be as non-intrusive as possible, we'll just make that call if
the clock had non-default boundaries.
Also add a few tests to make sure this case is covered.
Fixes: c80ac50cbb37 ("clk: Always set the rate on clk_set_range_rate")
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # imx8mp
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> # exynos4210, meson g12b
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-3-maxime@cerno.tech
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/clk/clk.c | 45 | ||||
-rw-r--r-- | drivers/clk/clk_test.c | 110 |
2 files changed, 141 insertions, 14 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 7fc191c15507..a5e0ab8bd6be 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2325,19 +2325,15 @@ 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; @@ -2350,8 +2346,6 @@ 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); @@ -2395,6 +2389,28 @@ 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; @@ -4348,9 +4364,10 @@ 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); + + /* If we had any boundaries on that clock, let's drop them. */ + if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX) + 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 7646356f30cb..7d9da88c39ee 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -793,9 +793,66 @@ static void clk_range_test_multiple_set_range_rate_maximized(struct kunit *test) clk_put(clk); } +/* + * 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 = clk_hw_get_clk(hw, NULL); + 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); + clk_put(clk); +} + 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), {} }; @@ -913,9 +970,62 @@ static void clk_range_test_multiple_set_range_rate_minimized(struct kunit *test) clk_put(clk); } +/* + * 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 = clk_hw_get_clk(hw, NULL); + 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); + clk_put(clk); +} + 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), {} }; |