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, 41 insertions, 0 deletions

diff --git a/drivers/gpib/include/gpibP.h b/drivers/gpib/include/gpibP.h
new file mode 100644
index 000000000..e3938ada3
--- /dev/null
+++ b/drivers/gpib/include/gpibP.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/***************************************************************************
+ *    copyright		   : (C) 2002,2003 by Frank Mori Hess
+ ***************************************************************************/
+
+#ifndef _GPIB_P_H
+#define _GPIB_P_H
+
+#include <linux/types.h>
+
+#include "gpib_types.h"
+#include "gpib_proto.h"
+#include "gpib_cmd.h"
+#include <linux/gpib.h>
+#include <linux/gpib_ioctl.h>
+
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+
+int gpib_register_driver(struct gpib_interface *interface, struct module *mod);
+void gpib_unregister_driver(struct gpib_interface *interface);
+struct pci_dev *gpib_pci_get_device(const struct gpib_board_config *config, unsigned int vendor_id,
+				    unsigned int device_id, struct pci_dev *from);
+struct pci_dev *gpib_pci_get_subsys(const struct gpib_board_config *config, unsigned int vendor_id,
+				    unsigned int device_id, unsigned int ss_vendor,
+				    unsigned int ss_device, struct pci_dev *from);
+unsigned int num_gpib_events(const struct gpib_event_queue *queue);
+int push_gpib_event(struct gpib_board *board, short event_type);
+int pop_gpib_event(struct gpib_board *board, struct gpib_event_queue *queue, short *event_type);
+int gpib_request_pseudo_irq(struct gpib_board *board, irqreturn_t (*handler)(int, void *));
+void gpib_free_pseudo_irq(struct gpib_board *board);
+int gpib_match_device_path(struct device *dev, const char *device_path_in);
+
+extern struct gpib_board board_array[GPIB_MAX_NUM_BOARDS];
+
+extern struct list_head registered_drivers;
+
+#endif	// _GPIB_P_H
+