From 3afb07231d603d51dca6a5d5e16d9d8f422f9b5f Mon Sep 17 00:00:00 2001 From: Maxime Ripard Date: Tue, 16 Aug 2022 13:25:17 +0200 Subject: clk: Take into account uncached clocks in clk_set_rate_range() clk_set_rate_range() will use the last requested rate for the clock when it calls into the driver set_rate hook. However, if CLK_GET_RATE_NOCACHE is set on that clock, the last requested rate might not be matching the current rate of the clock. In such a case, let's read out the rate from the hardware and use that in our set_rate instead. Tested-by: Alexander Stein # imx8mp Tested-by: Marek Szyprowski # exynos4210, meson g12b Signed-off-by: Maxime Ripard Link: https://lore.kernel.org/r/20220816112530.1837489-13-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing Tested-by: Naresh Kamboju Signed-off-by: Stephen Boyd --- drivers/clk/clk.c | 6 +++++- drivers/clk/clk_test.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 1 deletion(-) (limited to 'drivers/clk') diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index caa2eb640441..53b28e63deae 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -2373,6 +2373,10 @@ static int clk_set_rate_range_nolock(struct clk *clk, goto out; } + rate = clk->core->req_rate; + if (clk->core->flags & CLK_GET_RATE_NOCACHE) + rate = clk_core_get_rate_recalc(clk->core); + /* * Since the boundaries have been changed, let's give the * opportunity to the provider to adjust the clock rate based on @@ -2390,7 +2394,7 @@ static int clk_set_rate_range_nolock(struct clk *clk, * - the determine_rate() callback does not really check for * this corner case when determining the rate */ - rate = clamp(clk->core->req_rate, min, max); + rate = clamp(rate, min, max); ret = clk_core_set_rate_nolock(clk->core, rate); if (ret) { /* rollback the changes */ diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c index ceed49c5a88b..d3e121f21ae2 100644 --- a/drivers/clk/clk_test.c +++ b/drivers/clk/clk_test.c @@ -375,9 +375,40 @@ static void clk_test_uncached_set_range(struct kunit *test) clk_put(clk); } +/* + * Test that for an uncached clock, clk_set_rate_range() will work + * properly if the rate has changed in hardware. + * + * In this case, it means that if the rate wasn't initially in the range + * we're trying to set, but got changed at some point into the range + * without the kernel knowing about it, its rate shouldn't be affected. + */ +static void clk_test_uncached_updated_rate_set_range(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); + unsigned long rate; + + /* We change the rate behind the clock framework's back */ + ctx->rate = DUMMY_CLOCK_RATE_1 + 1000; + KUNIT_ASSERT_EQ(test, + clk_set_rate_range(clk, + DUMMY_CLOCK_RATE_1, + DUMMY_CLOCK_RATE_2), + 0); + + rate = clk_get_rate(clk); + KUNIT_ASSERT_GT(test, rate, 0); + KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1 + 1000); + + clk_put(clk); +} + static struct kunit_case clk_uncached_test_cases[] = { KUNIT_CASE(clk_test_uncached_get_rate), KUNIT_CASE(clk_test_uncached_set_range), + KUNIT_CASE(clk_test_uncached_updated_rate_set_range), {} }; -- cgit v1.2.3