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, 224 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
new file mode 100644
index 000000000..b4f44999e
--- /dev/null
+++ b/drivers/rtc/rtc-efi.c
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * rtc-efi: RTC Class Driver for EFI-based systems
+ *
+ * Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
+ *
+ * Author: dann frazier <dannf@dannf.org>
+ * Based on efirtc.c by Stephane Eranian
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/stringify.h>
+#include <linux/time.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+#include <linux/efi.h>
+
+#define EFI_ISDST (EFI_TIME_ADJUST_DAYLIGHT|EFI_TIME_IN_DAYLIGHT)
+
+/*
+ * returns day of the year [0-365]
+ */
+static inline int
+compute_yday(efi_time_t *eft)
+{
+	/* efi_time_t.month is in the [1-12] so, we need -1 */
+	return rtc_year_days(eft->day, eft->month - 1, eft->year);
+}
+
+/*
+ * returns day of the week [0-6] 0=Sunday
+ */
+static int
+compute_wday(efi_time_t *eft, int yday)
+{
+	int ndays = eft->year * (365 % 7)
+		    + (eft->year - 1) / 4
+		    - (eft->year - 1) / 100
+		    + (eft->year - 1) / 400
+		    + yday;
+
+	/*
+	 * 1/1/0000 may or may not have been a Sunday (if it ever existed at
+	 * all) but assuming it was makes this calculation work correctly.
+	 */
+	return ndays % 7;
+}
+
+static void
+convert_to_efi_time(struct rtc_time *wtime, efi_time_t *eft)
+{
+	eft->year	= wtime->tm_year + 1900;
+	eft->month	= wtime->tm_mon + 1;
+	eft->day	= wtime->tm_mday;
+	eft->hour	= wtime->tm_hour;
+	eft->minute	= wtime->tm_min;
+	eft->second	= wtime->tm_sec;
+	eft->nanosecond = 0;
+	eft->daylight	= wtime->tm_isdst ? EFI_ISDST : 0;
+	eft->timezone	= EFI_UNSPECIFIED_TIMEZONE;
+}
+
+static bool
+convert_from_efi_time(efi_time_t *eft, struct rtc_time *wtime)
+{
+	memset(wtime, 0, sizeof(*wtime));
+
+	if (eft->second >= 60)
+		return false;
+	wtime->tm_sec  = eft->second;
+
+	if (eft->minute >= 60)
+		return false;
+	wtime->tm_min  = eft->minute;
+
+	if (eft->hour >= 24)
+		return false;
+	wtime->tm_hour = eft->hour;
+
+	if (!eft->day || eft->day > 31)
+		return false;
+	wtime->tm_mday = eft->day;
+
+	if (!eft->month || eft->month > 12)
+		return false;
+	wtime->tm_mon  = eft->month - 1;
+
+	if (eft->year < 1900 || eft->year > 9999)
+		return false;
+	wtime->tm_year = eft->year - 1900;
+
+	/* day in the year [1-365]*/
+	wtime->tm_yday = compute_yday(eft);
+
+	/* day of the week [0-6], Sunday=0 */
+	wtime->tm_wday = compute_wday(eft, wtime->tm_yday);
+
+	switch (eft->daylight & EFI_ISDST) {
+	case EFI_ISDST:
+		wtime->tm_isdst = 1;
+		break;
+	case EFI_TIME_ADJUST_DAYLIGHT:
+		wtime->tm_isdst = 0;
+		break;
+	default:
+		wtime->tm_isdst = -1;
+	}
+
+	return true;
+}
+
+static int efi_read_time(struct device *dev, struct rtc_time *tm)
+{
+	efi_status_t status;
+	efi_time_t eft;
+	efi_time_cap_t cap;
+
+	status = efi.get_time(&eft, &cap);
+
+	if (status != EFI_SUCCESS) {
+		/* should never happen */
+		dev_err_once(dev, "can't read time\n");
+		return -EINVAL;
+	}
+
+	if (!convert_from_efi_time(&eft, tm))
+		return -EIO;
+
+	return 0;
+}
+
+static int efi_set_time(struct device *dev, struct rtc_time *tm)
+{
+	efi_status_t status;
+	efi_time_t eft;
+
+	convert_to_efi_time(tm, &eft);
+
+	status = efi.set_time(&eft);
+
+	return status == EFI_SUCCESS ? 0 : -EINVAL;
+}
+
+static int efi_procfs(struct device *dev, struct seq_file *seq)
+{
+	efi_time_t        eft;
+	efi_time_cap_t    cap;
+
+	memset(&eft, 0, sizeof(eft));
+	memset(&cap, 0, sizeof(cap));
+
+	efi.get_time(&eft, &cap);
+
+	seq_printf(seq,
+		   "Time\t\t: %u:%u:%u.%09u\n"
+		   "Date\t\t: %u-%u-%u\n"
+		   "Daylight\t: %u\n",
+		   eft.hour, eft.minute, eft.second, eft.nanosecond,
+		   eft.year, eft.month, eft.day,
+		   eft.daylight);
+
+	if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
+		seq_puts(seq, "Timezone\t: unspecified\n");
+	else
+		/* XXX fixme: convert to string? */
+		seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
+
+	/*
+	 * now prints the capabilities
+	 */
+	seq_printf(seq,
+		   "Resolution\t: %u\n"
+		   "Accuracy\t: %u\n"
+		   "SetstoZero\t: %u\n",
+		   cap.resolution, cap.accuracy, cap.sets_to_zero);
+
+	return 0;
+}
+
+static const struct rtc_class_ops efi_rtc_ops = {
+	.read_time	= efi_read_time,
+	.set_time	= efi_set_time,
+	.proc		= efi_procfs,
+};
+
+static int __init efi_rtc_probe(struct platform_device *dev)
+{
+	struct rtc_device *rtc;
+	efi_time_t eft;
+	efi_time_cap_t cap;
+
+	/* First check if the RTC is usable */
+	if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
+		return -ENODEV;
+
+	rtc = devm_rtc_allocate_device(&dev->dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	platform_set_drvdata(dev, rtc);
+
+	rtc->ops = &efi_rtc_ops;
+	clear_bit(RTC_FEATURE_ALARM, rtc->features);
+
+	device_init_wakeup(&dev->dev, true);
+
+	return devm_rtc_register_device(rtc);
+}
+
+static struct platform_driver efi_rtc_driver = {
+	.driver = {
+		.name = "rtc-efi",
+	},
+};
+
+module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
+
+MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("EFI RTC driver");
+MODULE_ALIAS("platform:rtc-efi");