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, 210 insertions, 0 deletions

diff --git a/drivers/ssb/host_soc.c b/drivers/ssb/host_soc.c
new file mode 100644
index 000000000..3b4384805
--- /dev/null
+++ b/drivers/ssb/host_soc.c
@@ -0,0 +1,210 @@
+/*
+ * Sonics Silicon Backplane SoC host related functions.
+ * Subsystem core
+ *
+ * Copyright 2005, Broadcom Corporation
+ * Copyright 2006, 2007, Michael Buesch <m@bues.ch>
+ *
+ * Licensed under the GNU/GPL. See COPYING for details.
+ */
+
+#include "ssb_private.h"
+
+#include <linux/bcm47xx_nvram.h>
+#include <linux/ssb/ssb.h>
+
+static u8 ssb_host_soc_read8(struct ssb_device *dev, u16 offset)
+{
+	struct ssb_bus *bus = dev->bus;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	return readb(bus->mmio + offset);
+}
+
+static u16 ssb_host_soc_read16(struct ssb_device *dev, u16 offset)
+{
+	struct ssb_bus *bus = dev->bus;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	return readw(bus->mmio + offset);
+}
+
+static u32 ssb_host_soc_read32(struct ssb_device *dev, u16 offset)
+{
+	struct ssb_bus *bus = dev->bus;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	return readl(bus->mmio + offset);
+}
+
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_host_soc_block_read(struct ssb_device *dev, void *buffer,
+				    size_t count, u16 offset, u8 reg_width)
+{
+	struct ssb_bus *bus = dev->bus;
+	void __iomem *addr;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	addr = bus->mmio + offset;
+
+	switch (reg_width) {
+	case sizeof(u8): {
+		u8 *buf = buffer;
+
+		while (count) {
+			*buf = __raw_readb(addr);
+			buf++;
+			count--;
+		}
+		break;
+	}
+	case sizeof(u16): {
+		__le16 *buf = buffer;
+
+		WARN_ON(count & 1);
+		while (count) {
+			*buf = (__force __le16)__raw_readw(addr);
+			buf++;
+			count -= 2;
+		}
+		break;
+	}
+	case sizeof(u32): {
+		__le32 *buf = buffer;
+
+		WARN_ON(count & 3);
+		while (count) {
+			*buf = (__force __le32)__raw_readl(addr);
+			buf++;
+			count -= 4;
+		}
+		break;
+	}
+	default:
+		WARN_ON(1);
+	}
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
+static void ssb_host_soc_write8(struct ssb_device *dev, u16 offset, u8 value)
+{
+	struct ssb_bus *bus = dev->bus;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	writeb(value, bus->mmio + offset);
+}
+
+static void ssb_host_soc_write16(struct ssb_device *dev, u16 offset, u16 value)
+{
+	struct ssb_bus *bus = dev->bus;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	writew(value, bus->mmio + offset);
+}
+
+static void ssb_host_soc_write32(struct ssb_device *dev, u16 offset, u32 value)
+{
+	struct ssb_bus *bus = dev->bus;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	writel(value, bus->mmio + offset);
+}
+
+#ifdef CONFIG_SSB_BLOCKIO
+static void ssb_host_soc_block_write(struct ssb_device *dev, const void *buffer,
+				     size_t count, u16 offset, u8 reg_width)
+{
+	struct ssb_bus *bus = dev->bus;
+	void __iomem *addr;
+
+	offset += dev->core_index * SSB_CORE_SIZE;
+	addr = bus->mmio + offset;
+
+	switch (reg_width) {
+	case sizeof(u8): {
+		const u8 *buf = buffer;
+
+		while (count) {
+			__raw_writeb(*buf, addr);
+			buf++;
+			count--;
+		}
+		break;
+	}
+	case sizeof(u16): {
+		const __le16 *buf = buffer;
+
+		WARN_ON(count & 1);
+		while (count) {
+			__raw_writew((__force u16)(*buf), addr);
+			buf++;
+			count -= 2;
+		}
+		break;
+	}
+	case sizeof(u32): {
+		const __le32 *buf = buffer;
+
+		WARN_ON(count & 3);
+		while (count) {
+			__raw_writel((__force u32)(*buf), addr);
+			buf++;
+			count -= 4;
+		}
+		break;
+	}
+	default:
+		WARN_ON(1);
+	}
+}
+#endif /* CONFIG_SSB_BLOCKIO */
+
+/* Ops for the plain SSB bus without a host-device (no PCI or PCMCIA). */
+const struct ssb_bus_ops ssb_host_soc_ops = {
+	.read8		= ssb_host_soc_read8,
+	.read16		= ssb_host_soc_read16,
+	.read32		= ssb_host_soc_read32,
+	.write8		= ssb_host_soc_write8,
+	.write16	= ssb_host_soc_write16,
+	.write32	= ssb_host_soc_write32,
+#ifdef CONFIG_SSB_BLOCKIO
+	.block_read	= ssb_host_soc_block_read,
+	.block_write	= ssb_host_soc_block_write,
+#endif
+};
+
+int ssb_host_soc_get_invariants(struct ssb_bus *bus,
+				struct ssb_init_invariants *iv)
+{
+	char buf[20];
+	int len, err;
+
+	/* Fill boardinfo structure */
+	memset(&iv->boardinfo, 0, sizeof(struct ssb_boardinfo));
+
+	len = bcm47xx_nvram_getenv("boardvendor", buf, sizeof(buf));
+	if (len > 0) {
+		err = kstrtou16(strim(buf), 0, &iv->boardinfo.vendor);
+		if (err)
+			pr_warn("Couldn't parse nvram board vendor entry with value \"%s\"\n",
+				buf);
+	}
+	if (!iv->boardinfo.vendor)
+		iv->boardinfo.vendor = SSB_BOARDVENDOR_BCM;
+
+	len = bcm47xx_nvram_getenv("boardtype", buf, sizeof(buf));
+	if (len > 0) {
+		err = kstrtou16(strim(buf), 0, &iv->boardinfo.type);
+		if (err)
+			pr_warn("Couldn't parse nvram board type entry with value \"%s\"\n",
+				buf);
+	}
+
+	memset(&iv->sprom, 0, sizeof(struct ssb_sprom));
+	ssb_fill_sprom_with_fallback(bus, &iv->sprom);
+
+	if (bcm47xx_nvram_getenv("cardbus", buf, sizeof(buf)) >= 0)
+		iv->has_cardbus_slot = !!simple_strtoul(buf, NULL, 10);
+
+	return 0;
+}