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, 26 insertions, 0 deletions

diff --git a/drivers/misc/keba/Kconfig b/drivers/misc/keba/Kconfig
new file mode 100644
index 000000000..d6d47197a
--- /dev/null
+++ b/drivers/misc/keba/Kconfig
@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: GPL-2.0
+config KEBA_CP500
+	tristate "KEBA CP500 system FPGA support"
+	depends on X86_64 || ARM64 || COMPILE_TEST
+	depends on PCI
+	depends on I2C
+	select AUXILIARY_BUS
+	help
+	  This driver supports the KEBA CP500 system FPGA, which is used in
+	  KEBA CP500 devices. It registers all sub devices present on the CP500
+	  system FPGA as separate devices. A driver is needed for each sub
+	  device.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called cp500.
+
+config KEBA_LAN9252
+	tristate "KEBA CP500 LAN9252 configuration"
+	depends on SPI
+	depends on KEBA_CP500 || COMPILE_TEST
+	help
+	  This driver is used for updating the configuration of the LAN9252
+	  controller on KEBA CP500 devices.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called lan9252.