1 files changed, 124 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.15/950-0840-clk-tests-Add-tests-for-uncached-clock.patch b/target/linux/bcm27xx/patches-5.15/950-0840-clk-tests-Add-tests-for-uncached-clock.patch
new file mode 100644
index 0000000000..3db0743490
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.15/950-0840-clk-tests-Add-tests-for-uncached-clock.patch
@@ -0,0 +1,124 @@
+From b28798f3ae1a63169dd57e5b5cb55848172aa4c6 Mon Sep 17 00:00:00 2001
+From: Maxime Ripard <maxime@cerno.tech>
+Date: Fri, 8 Apr 2022 09:54:39 +0200
+Subject: [PATCH] clk: tests: Add tests for uncached clock
+
+The clock framework supports clocks that can have their rate changed
+without the kernel knowing about it using the CLK_GET_RATE_NOCACHE flag.
+
+As its name suggests, this flag turns off the rate caching in the clock
+framework, reading out the rate from the hardware any time we need to
+read it.
+
+Let's add a couple of tests to make sure it works as intended.
+
+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>
+---
+ drivers/clk/clk_test.c | 88 +++++++++++++++++++++++++++++++++++++++++-
+ 1 file changed, 87 insertions(+), 1 deletion(-)
+
+--- a/drivers/clk/clk_test.c
++++ b/drivers/clk/clk_test.c
+@@ -262,6 +262,91 @@ static struct kunit_suite clk_test_suite
+ 	.test_cases = clk_test_cases,
+ };
+ 
++static int clk_uncached_test_init(struct kunit *test)
++{
++	struct clk_dummy_context *ctx;
++	int ret;
++
++	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
++	if (!ctx)
++		return -ENOMEM;
++	test->priv = ctx;
++
++	ctx->rate = DUMMY_CLOCK_INIT_RATE;
++	ctx->hw.init = CLK_HW_INIT_NO_PARENT("test-clk",
++					     &clk_dummy_rate_ops,
++					     CLK_GET_RATE_NOCACHE);
++
++	ret = clk_hw_register(NULL, &ctx->hw);
++	if (ret)
++		return ret;
++
++	return 0;
++}
++
++/*
++ * Test that for an uncached clock, the clock framework doesn't cache
++ * the rate and clk_get_rate() will return the underlying clock rate
++ * even if it changed.
++ */
++static void clk_test_uncached_get_rate(struct kunit *test)
++{
++	struct clk_dummy_context *ctx = test->priv;
++	struct clk_hw *hw = &ctx->hw;
++	struct clk *clk = hw->clk;
++	unsigned long rate;
++
++	rate = clk_get_rate(clk);
++	KUNIT_ASSERT_GT(test, rate, 0);
++	KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_INIT_RATE);
++
++	ctx->rate = DUMMY_CLOCK_RATE_1;
++	rate = clk_get_rate(clk);
++	KUNIT_ASSERT_GT(test, rate, 0);
++	KUNIT_EXPECT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
++}
++
++/*
++ * Test that for an uncached clock, clk_set_rate_range() will work
++ * properly if the rate hasn't changed.
++ */
++static void clk_test_uncached_set_range(struct kunit *test)
++{
++	struct clk_dummy_context *ctx = test->priv;
++	struct clk_hw *hw = &ctx->hw;
++	struct clk *clk = hw->clk;
++	unsigned long rate;
++
++	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_GE(test, rate, DUMMY_CLOCK_RATE_1);
++	KUNIT_EXPECT_LE(test, rate, DUMMY_CLOCK_RATE_2);
++}
++
++static struct kunit_case clk_uncached_test_cases[] = {
++	KUNIT_CASE(clk_test_uncached_get_rate),
++	KUNIT_CASE(clk_test_uncached_set_range),
++	{}
++};
++
++/*
++ * Test suite for a basic, uncached, rate clock, without any parent.
++ *
++ * These tests are supposed to exercise the rate API with simple scenarios
++ */
++static struct kunit_suite clk_uncached_test_suite = {
++	.name = "clk-uncached-test",
++	.init = clk_uncached_test_init,
++	.exit = clk_test_exit,
++	.test_cases = clk_uncached_test_cases,
++};
++
+ struct clk_single_parent_ctx {
+ 	struct clk_dummy_context parent_ctx;
+ 	struct clk_hw hw;
+@@ -1042,6 +1127,7 @@ kunit_test_suites(
+ 	&clk_orphan_transparent_single_parent_test_suite,
+ 	&clk_range_test_suite,
+ 	&clk_range_maximize_test_suite,
+-	&clk_range_minimize_test_suite
++	&clk_range_minimize_test_suite,
++	&clk_uncached_test_suite
+ );
+ MODULE_LICENSE("GPL v2");