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, 86 insertions, 0 deletions

diff --git a/drivers/comedi/comedi_internal.h b/drivers/comedi/comedi_internal.h
new file mode 100644
index 000000000..41a3b09f8
--- /dev/null
+++ b/drivers/comedi/comedi_internal.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _COMEDI_INTERNAL_H
+#define _COMEDI_INTERNAL_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+/*
+ * various internal comedi stuff
+ */
+
+struct comedi_buf_map;
+struct comedi_devconfig;
+struct comedi_device;
+struct comedi_insn;
+struct comedi_rangeinfo;
+struct comedi_subdevice;
+struct device;
+
+int do_rangeinfo_ioctl(struct comedi_device *dev,
+		       struct comedi_rangeinfo *it);
+struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device);
+void comedi_release_hardware_device(struct device *hardware_device);
+int comedi_alloc_subdevice_minor(struct comedi_subdevice *s);
+void comedi_free_subdevice_minor(struct comedi_subdevice *s);
+
+int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
+		     unsigned long new_size);
+void comedi_buf_reset(struct comedi_subdevice *s);
+bool comedi_buf_is_mmapped(struct comedi_subdevice *s);
+void comedi_buf_map_get(struct comedi_buf_map *bm);
+int comedi_buf_map_put(struct comedi_buf_map *bm);
+int comedi_buf_map_access(struct comedi_buf_map *bm, unsigned long offset,
+			  void *buf, int len, int write);
+struct comedi_buf_map *
+comedi_buf_map_from_subdev_get(struct comedi_subdevice *s);
+unsigned int comedi_buf_write_n_available(struct comedi_subdevice *s);
+unsigned int comedi_buf_write_n_allocated(struct comedi_subdevice *s);
+unsigned int _comedi_buf_write_alloc(struct comedi_subdevice *s,
+				     unsigned int nbytes);
+unsigned int _comedi_buf_write_free(struct comedi_subdevice *s,
+				    unsigned int nbytes);
+unsigned int _comedi_buf_read_n_available(struct comedi_subdevice *s);
+unsigned int _comedi_buf_read_alloc(struct comedi_subdevice *s,
+				    unsigned int nbytes);
+unsigned int _comedi_buf_read_free(struct comedi_subdevice *s,
+				   unsigned int nbytes);
+void _comedi_inc_scan_progress(struct comedi_subdevice *s,
+			       unsigned int num_bytes);
+void _comedi_event(struct comedi_device *dev, struct comedi_subdevice *s);
+void comedi_device_cancel_all(struct comedi_device *dev);
+bool comedi_can_auto_free_spriv(struct comedi_subdevice *s);
+
+extern unsigned int comedi_default_buf_size_kb;
+extern unsigned int comedi_default_buf_maxsize_kb;
+
+/* drivers.c */
+
+extern struct comedi_driver *comedi_drivers;
+extern struct mutex comedi_drivers_list_lock;
+
+int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
+	       struct comedi_insn *insn, unsigned int *data);
+
+void comedi_device_detach_locked(struct comedi_device *dev);
+void comedi_device_detach(struct comedi_device *dev);
+int comedi_device_attach(struct comedi_device *dev,
+			 struct comedi_devconfig *it);
+
+#ifdef CONFIG_PROC_FS
+
+/* proc.c */
+
+void comedi_proc_init(void);
+void comedi_proc_cleanup(void);
+#else
+static inline void comedi_proc_init(void)
+{
+}
+
+static inline void comedi_proc_cleanup(void)
+{
+}
+#endif
+
+#endif /* _COMEDI_INTERNAL_H */