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, 172 insertions, 0 deletions

diff --git a/include/net/codel.h b/include/net/codel.h
new file mode 100644
index 000000000..183d43c2b
--- /dev/null
+++ b/include/net/codel.h
@@ -0,0 +1,172 @@
+#ifndef __NET_SCHED_CODEL_H
+#define __NET_SCHED_CODEL_H
+
+/*
+ * Codel - The Controlled-Delay Active Queue Management algorithm
+ *
+ *  Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com>
+ *  Copyright (C) 2011-2012 Van Jacobson <van@pollere.net>
+ *  Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net>
+ *  Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The names of the authors may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/ktime.h>
+#include <linux/skbuff.h>
+
+/* Controlling Queue Delay (CoDel) algorithm
+ * =========================================
+ * Source : Kathleen Nichols and Van Jacobson
+ * http://queue.acm.org/detail.cfm?id=2209336
+ *
+ * Implemented on linux by Dave Taht and Eric Dumazet
+ */
+
+
+/* CoDel uses a 1024 nsec clock, encoded in u32
+ * This gives a range of 2199 seconds, because of signed compares
+ */
+typedef u32 codel_time_t;
+typedef s32 codel_tdiff_t;
+#define CODEL_SHIFT 10
+#define MS2TIME(a) ((a * NSEC_PER_MSEC) >> CODEL_SHIFT)
+
+static inline codel_time_t codel_get_time(void)
+{
+	u64 ns = ktime_get_ns();
+
+	return ns >> CODEL_SHIFT;
+}
+
+/* Dealing with timer wrapping, according to RFC 1982, as desc in wikipedia:
+ *  https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution
+ * codel_time_after(a,b) returns true if the time a is after time b.
+ */
+#define codel_time_after(a, b)						\
+	(typecheck(codel_time_t, a) &&					\
+	 typecheck(codel_time_t, b) &&					\
+	 ((s32)((a) - (b)) > 0))
+#define codel_time_before(a, b) 	codel_time_after(b, a)
+
+#define codel_time_after_eq(a, b)					\
+	(typecheck(codel_time_t, a) &&					\
+	 typecheck(codel_time_t, b) &&					\
+	 ((s32)((a) - (b)) >= 0))
+#define codel_time_before_eq(a, b)	codel_time_after_eq(b, a)
+
+static inline u32 codel_time_to_us(codel_time_t val)
+{
+	u64 valns = ((u64)val << CODEL_SHIFT);
+
+	do_div(valns, NSEC_PER_USEC);
+	return (u32)valns;
+}
+
+/**
+ * struct codel_params - contains codel parameters
+ * @target:	target queue size (in time units)
+ * @ce_threshold:  threshold for marking packets with ECN CE
+ * @interval:	width of moving time window
+ * @mtu:	device mtu, or minimal queue backlog in bytes.
+ * @ecn:	is Explicit Congestion Notification enabled
+ * @ce_threshold_selector: apply ce_threshold to packets matching this value
+ *                         in the diffserv/ECN byte of the IP header
+ * @ce_threshold_mask: mask to apply to ce_threshold_selector comparison
+ */
+struct codel_params {
+	codel_time_t	target;
+	codel_time_t	ce_threshold;
+	codel_time_t	interval;
+	u32		mtu;
+	bool		ecn;
+	u8		ce_threshold_selector;
+	u8		ce_threshold_mask;
+};
+
+/**
+ * struct codel_vars - contains codel variables
+ * @count:		how many drops we've done since the last time we
+ *			entered dropping state
+ * @lastcount:		count at entry to dropping state
+ * @dropping:		set to true if in dropping state
+ * @rec_inv_sqrt:	reciprocal value of sqrt(count) >> 1
+ * @first_above_time:	when we went (or will go) continuously above target
+ *			for interval
+ * @drop_next:		time to drop next packet, or when we dropped last
+ * @ldelay:		sojourn time of last dequeued packet
+ */
+struct codel_vars {
+	u32		count;
+	u32		lastcount;
+	bool		dropping;
+	u16		rec_inv_sqrt;
+	codel_time_t	first_above_time;
+	codel_time_t	drop_next;
+	codel_time_t	ldelay;
+};
+
+#define REC_INV_SQRT_BITS (8 * sizeof(u16)) /* or sizeof_in_bits(rec_inv_sqrt) */
+/* needed shift to get a Q0.32 number from rec_inv_sqrt */
+#define REC_INV_SQRT_SHIFT (32 - REC_INV_SQRT_BITS)
+
+/* Cap on drops per codel_dequeue() call: the loop's work depends on the
+ * idle gap and backlog, both outside our control; resync when exceeded.
+ */
+#define CODEL_MAX_DROPS_PER_DEQUEUE 256
+
+/**
+ * struct codel_stats - contains codel shared variables and stats
+ * @maxpacket:	largest packet we've seen so far
+ * @drop_count:	temp count of dropped packets in dequeue()
+ * @drop_len:	bytes of dropped packets in dequeue()
+ * @ecn_mark:	number of packets we ECN marked instead of dropping
+ * @ce_mark:	number of packets CE marked because sojourn time was above ce_threshold
+ */
+struct codel_stats {
+	u32		maxpacket;
+	u32		drop_count;
+	u32		drop_len;
+	u32		ecn_mark;
+	u32		ce_mark;
+};
+
+#define CODEL_DISABLED_THRESHOLD INT_MAX
+
+typedef u32 (*codel_skb_len_t)(const struct sk_buff *skb);
+typedef codel_time_t (*codel_skb_time_t)(const struct sk_buff *skb);
+typedef void (*codel_skb_drop_t)(struct sk_buff *skb, void *ctx);
+typedef struct sk_buff * (*codel_skb_dequeue_t)(struct codel_vars *vars,
+						void *ctx);
+
+#endif