drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validationgrafted

amdgpu_dm_create_validate_stream_for_sink() walks encoding_order[] and
uses the first encoding that validates. YCbCr 4:4:4 is listed before
RGB, so an HDMI sink that advertises 4:4:4 gets YCbCr 4:4:4 whenever the
"color format" property is left at AUTO, even though RGB fits the same
link.

That contradicts the documented AUTO behaviour for HDMI in enum
drm_connector_color_format (RGB, falling back to YCbCr 4:2:0 only when
the bandwidth is not available or the mode is 4:2:0-only), which the
amdgpu implementation of the property also describes. It also leaves
the "Broadcast RGB" property without effect on such sinks, since the
quantization range it selects only applies to RGB output.

Try RGB first. The mask still holds every encoding the sink supports,
so a mode that cannot carry RGB falls back exactly as before.

For reference, v7.2 picked RGB here unless YCbCr 4:4:4 was forced
through debugfs, while earlier kernels picked YCbCr 4:4:4 for any HDMI
sink that advertised it.

Fixes: 0b0ff65d3ca1 ("drm/amd/display: Refactor stream validation")
Suggested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Assisted-by: Claude Code:claude-fable-5-1
Signed-off-by: Adrian Betschart <adrian.betschart@cinemaone.ch>
Reviewed-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Adolfo Rodrigues <adolfotregosa@gmail.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7)

1 files changed, 159 insertions, 0 deletions

diff --git a/lib/tests/test_bits.c b/lib/tests/test_bits.c
new file mode 100644
index 000000000..ab88e50d2
--- /dev/null
+++ b/lib/tests/test_bits.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test cases for functions and macros in bits.h
+ */
+
+#include <kunit/test.h>
+#include <linux/bits.h>
+#include <linux/types.h>
+
+#define assert_type(t, x) _Generic(x, t: x, default: 0)
+
+static_assert(assert_type(u8, BIT_U8(0)) == 1u);
+static_assert(assert_type(u16, BIT_U16(0)) == 1u);
+static_assert(assert_type(u32, BIT_U32(0)) == 1u);
+static_assert(assert_type(u64, BIT_U64(0)) == 1ull);
+
+static_assert(assert_type(u8, BIT_U8(7)) == 0x80u);
+static_assert(assert_type(u16, BIT_U16(15)) == 0x8000u);
+static_assert(assert_type(u32, BIT_U32(31)) == 0x80000000u);
+static_assert(assert_type(u64, BIT_U64(63)) == 0x8000000000000000ull);
+
+static_assert(assert_type(unsigned long, GENMASK(31, 0)) == U32_MAX);
+static_assert(assert_type(unsigned long long, GENMASK_ULL(63, 0)) == U64_MAX);
+static_assert(assert_type(u8, GENMASK_U8(7, 0)) == U8_MAX);
+static_assert(assert_type(u16, GENMASK_U16(15, 0)) == U16_MAX);
+static_assert(assert_type(u32, GENMASK_U32(31, 0)) == U32_MAX);
+static_assert(assert_type(u64, GENMASK_U64(63, 0)) == U64_MAX);
+
+/* FIXME: add a test case written in asm for GENMASK() and GENMASK_ULL() */
+
+static void __genmask_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ul, __GENMASK(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ul, __GENMASK(1, 0));
+	KUNIT_EXPECT_EQ(test, 6ul, __GENMASK(2, 1));
+	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, __GENMASK(31, 0));
+}
+
+static void __genmask_ull_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ull, __GENMASK_ULL(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ull, __GENMASK_ULL(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, __GENMASK_ULL(39, 21));
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, __GENMASK_ULL(63, 0));
+}
+
+static void genmask_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ul, GENMASK(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ul, GENMASK(1, 0));
+	KUNIT_EXPECT_EQ(test, 6ul, GENMASK(2, 1));
+	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, GENMASK(31, 0));
+
+	KUNIT_EXPECT_EQ(test, 1u, GENMASK_U8(0, 0));
+	KUNIT_EXPECT_EQ(test, 3u, GENMASK_U16(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x10000, GENMASK_U32(16, 16));
+
+#ifdef TEST_GENMASK_FAILURES
+	/* these should fail compilation */
+	GENMASK(0, 1);
+	GENMASK(0, 10);
+	GENMASK(9, 10);
+
+	GENMASK_U32(0, 31);
+	GENMASK_U64(64, 0);
+	GENMASK_U32(32, 0);
+	GENMASK_U16(16, 0);
+	GENMASK_U8(8, 0);
+#endif
+
+
+}
+
+static void genmask_ull_test(struct kunit *test)
+{
+	KUNIT_EXPECT_EQ(test, 1ull, GENMASK_ULL(0, 0));
+	KUNIT_EXPECT_EQ(test, 3ull, GENMASK_ULL(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_ULL(39, 21));
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_ULL(63, 0));
+
+#ifdef TEST_GENMASK_FAILURES
+	/* these should fail compilation */
+	GENMASK_ULL(0, 1);
+	GENMASK_ULL(0, 10);
+	GENMASK_ULL(9, 10);
+#endif
+}
+
+static void genmask_u128_test(struct kunit *test)
+{
+#ifdef CONFIG_ARCH_SUPPORTS_INT128
+	/* Below 64 bit masks */
+	KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(0, 0));
+	KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x0000000000000006ull, GENMASK_U128(2, 1));
+	KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(31, 0));
+	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_U128(39, 21));
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(63, 0));
+
+	/* Above 64 bit masks - only 64 bit portion can be validated once */
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(64, 0) >> 1);
+	KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(81, 50) >> 50);
+	KUNIT_EXPECT_EQ(test, 0x0000000000ffffffull, GENMASK_U128(87, 64) >> 64);
+	KUNIT_EXPECT_EQ(test, 0x0000000000ff0000ull, GENMASK_U128(87, 80) >> 64);
+
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(127, 0) >> 64);
+	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, (u64)GENMASK_U128(127, 0));
+	KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(127, 126) >> 126);
+	KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(127, 127) >> 127);
+#ifdef TEST_GENMASK_FAILURES
+	/* these should fail compilation */
+	GENMASK_U128(0, 1);
+	GENMASK_U128(0, 10);
+	GENMASK_U128(9, 10);
+#endif /* TEST_GENMASK_FAILURES */
+#endif /* CONFIG_ARCH_SUPPORTS_INT128 */
+}
+
+static void genmask_input_check_test(struct kunit *test)
+{
+	unsigned int x, y;
+	int z, w;
+
+	/* Unknown input */
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, 0));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, x));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, y));
+
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, 0));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, z));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, w));
+
+	/* Valid input */
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(1, 1));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(39, 21));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(100, 80));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(110, 65));
+	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(127, 0));
+}
+
+
+static struct kunit_case bits_test_cases[] = {
+	KUNIT_CASE(__genmask_test),
+	KUNIT_CASE(__genmask_ull_test),
+	KUNIT_CASE(genmask_test),
+	KUNIT_CASE(genmask_ull_test),
+	KUNIT_CASE(genmask_u128_test),
+	KUNIT_CASE(genmask_input_check_test),
+	{}
+};
+
+static struct kunit_suite bits_test_suite = {
+	.name = "bits-test",
+	.test_cases = bits_test_cases,
+};
+kunit_test_suite(bits_test_suite);
+
+MODULE_DESCRIPTION("Test cases for functions and macros in bits.h");
+MODULE_LICENSE("GPL");