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, 85 insertions, 0 deletions

diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig
new file mode 100644
index 000000000..b78c644fa
--- /dev/null
+++ b/drivers/firmware/google/Kconfig
@@ -0,0 +1,85 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig GOOGLE_FIRMWARE
+	bool "Google Firmware Drivers"
+	default n
+	help
+	  These firmware drivers are used by Google servers,
+	  Chromebooks and other devices using coreboot firmware.
+	  If in doubt, say "N".
+
+if GOOGLE_FIRMWARE
+
+config GOOGLE_SMI
+	tristate "SMI interface for Google platforms"
+	depends on X86 && ACPI && DMI
+	help
+	  Say Y here if you want to enable SMI callbacks for Google
+	  platforms.  This provides an interface for writing to and
+	  clearing the event log.  If CONFIG_EFI is also enabled this
+	  driver provides an interface for reading and writing NVRAM
+	  variables.
+
+config GOOGLE_CBMEM
+	tristate "CBMEM entries in sysfs"
+	depends on GOOGLE_COREBOOT_TABLE
+	help
+	  CBMEM is a downwards-growing memory region created by the
+	  Coreboot BIOS containing tagged data structures from the
+	  BIOS.  These data structures expose things like the verified
+	  boot firmware variables, flash layout, firmware event log,
+	  and more.
+
+	  This option enables the cbmem module, which causes the
+	  kernel to search for Coreboot CBMEM entries, and expose the
+	  memory for each entry in sysfs under
+	  /sys/bus/coreboot/devices/cbmem-<id>.
+
+config GOOGLE_COREBOOT_TABLE
+	tristate "Coreboot Table Access"
+	depends on HAS_IOMEM && (ACPI || OF)
+	help
+	  This option enables the coreboot_table module, which provides other
+	  firmware modules access to the coreboot table. The coreboot table
+	  pointer is accessed through the ACPI "GOOGCB00" object or the
+	  device tree node /firmware/coreboot.
+	  If unsure say N.
+
+config GOOGLE_MEMCONSOLE
+	tristate
+	depends on GOOGLE_MEMCONSOLE_X86_LEGACY || GOOGLE_MEMCONSOLE_COREBOOT
+
+config GOOGLE_MEMCONSOLE_X86_LEGACY
+	tristate "Firmware Memory Console - X86 Legacy support"
+	depends on X86 && ACPI && DMI
+	select GOOGLE_MEMCONSOLE
+	help
+	  This option enables the kernel to search for a firmware log in
+	  the EBDA on Google servers.  If found, this log is exported to
+	  userland in the file /sys/firmware/log.
+
+config GOOGLE_FRAMEBUFFER_COREBOOT
+	tristate "Coreboot Framebuffer"
+	depends on GOOGLE_COREBOOT_TABLE
+	help
+	  This option enables the kernel to search for a framebuffer in
+	  the coreboot table.  If found, it is registered with a platform
+	  device of type coreboot-framebuffer. Using the old device of
+	  type simple-framebuffer is deprecated.
+
+config GOOGLE_MEMCONSOLE_COREBOOT
+	tristate "Firmware Memory Console"
+	depends on GOOGLE_COREBOOT_TABLE
+	select GOOGLE_MEMCONSOLE
+	help
+	  This option enables the kernel to search for a firmware log in
+	  the coreboot table.  If found, this log is exported to userland
+	  in the file /sys/firmware/log.
+
+config GOOGLE_VPD
+	tristate "Vital Product Data"
+	depends on GOOGLE_COREBOOT_TABLE
+	help
+	  This option enables the kernel to expose the content of Google VPD
+	  under /sys/firmware/vpd.
+
+endif # GOOGLE_FIRMWARE