From 106b4a2a78b2a2f14885604891957b84bba502db Mon Sep 17 00:00:00 2001 From: Adrian Betschart Date: Fri, 11 Sep 2026 17:13:14 +0200 Subject: drm/amd/display: Try RGB before YCbCr 4:4:4 in stream validation 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 Assisted-by: Claude Code:claude-fable-5-1 Signed-off-by: Adrian Betschart Reviewed-by: Fangzhi Zuo Tested-by: Adolfo Rodrigues Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher (cherry picked from commit 7de432bc753133764dc40d37f9388da56de251e7) --- drivers/base/regmap/regmap-ac97.c | 90 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 drivers/base/regmap/regmap-ac97.c (limited to 'drivers/base/regmap/regmap-ac97.c') diff --git a/drivers/base/regmap/regmap-ac97.c b/drivers/base/regmap/regmap-ac97.c new file mode 100644 index 000000000..a561971c4 --- /dev/null +++ b/drivers/base/regmap/regmap-ac97.c @@ -0,0 +1,90 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Register map access API - AC'97 support +// +// Copyright 2013 Linaro Ltd. All rights reserved. + +#include +#include +#include +#include +#include +#include +#include + +#include + +bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg) +{ + switch (reg) { + case AC97_RESET: + case AC97_POWERDOWN: + case AC97_INT_PAGING: + case AC97_EXTENDED_ID: + case AC97_EXTENDED_STATUS: + case AC97_EXTENDED_MID: + case AC97_EXTENDED_MSTATUS: + case AC97_GPIO_STATUS: + case AC97_MISC_AFE: + case AC97_VENDOR_ID1: + case AC97_VENDOR_ID2: + case AC97_CODEC_CLASS_REV: + case AC97_PCI_SVID: + case AC97_PCI_SID: + case AC97_FUNC_SELECT: + case AC97_FUNC_INFO: + case AC97_SENSE_INFO: + return true; + default: + return false; + } +} +EXPORT_SYMBOL_GPL(regmap_ac97_default_volatile); + +static int regmap_ac97_reg_read(void *context, unsigned int reg, + unsigned int *val) +{ + struct snd_ac97 *ac97 = context; + + *val = ac97->bus->ops->read(ac97, reg); + + return 0; +} + +static int regmap_ac97_reg_write(void *context, unsigned int reg, + unsigned int val) +{ + struct snd_ac97 *ac97 = context; + + ac97->bus->ops->write(ac97, reg, val); + + return 0; +} + +static const struct regmap_bus ac97_regmap_bus = { + .reg_write = regmap_ac97_reg_write, + .reg_read = regmap_ac97_reg_read, +}; + +struct regmap *__regmap_init_ac97(struct snd_ac97 *ac97, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + return __regmap_init(&ac97->dev, &ac97_regmap_bus, ac97, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__regmap_init_ac97); + +struct regmap *__devm_regmap_init_ac97(struct snd_ac97 *ac97, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + return __devm_regmap_init(&ac97->dev, &ac97_regmap_bus, ac97, config, + lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__devm_regmap_init_ac97); + +MODULE_DESCRIPTION("Register map access API - AC'97 support"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1