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-sdw.c | 102 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 drivers/base/regmap/regmap-sdw.c (limited to 'drivers/base/regmap/regmap-sdw.c') diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c new file mode 100644 index 000000000..ea631ac7c --- /dev/null +++ b/drivers/base/regmap/regmap-sdw.c @@ -0,0 +1,102 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright(c) 2015-17 Intel Corporation. + +#include +#include +#include +#include +#include +#include +#include "internal.h" + +static int regmap_sdw_write(void *context, const void *val_buf, size_t val_size) +{ + struct device *dev = context; + struct sdw_slave *slave = dev_to_sdw_dev(dev); + /* First word of buffer contains the destination address */ + u32 addr = le32_to_cpu(*(const __le32 *)val_buf); + const u8 *val = val_buf; + + return sdw_nwrite_no_pm(slave, addr, val_size - sizeof(addr), val + sizeof(addr)); +} + +static int regmap_sdw_gather_write(void *context, + const void *reg_buf, size_t reg_size, + const void *val_buf, size_t val_size) +{ + struct device *dev = context; + struct sdw_slave *slave = dev_to_sdw_dev(dev); + u32 addr = le32_to_cpu(*(const __le32 *)reg_buf); + + return sdw_nwrite_no_pm(slave, addr, val_size, val_buf); +} + +static int regmap_sdw_read(void *context, + const void *reg_buf, size_t reg_size, + void *val_buf, size_t val_size) +{ + struct device *dev = context; + struct sdw_slave *slave = dev_to_sdw_dev(dev); + u32 addr = le32_to_cpu(*(const __le32 *)reg_buf); + + return sdw_nread_no_pm(slave, addr, val_size, val_buf); +} + +static const struct regmap_bus regmap_sdw = { + .write = regmap_sdw_write, + .gather_write = regmap_sdw_gather_write, + .read = regmap_sdw_read, + .reg_format_endian_default = REGMAP_ENDIAN_LITTLE, + .val_format_endian_default = REGMAP_ENDIAN_LITTLE, +}; + +static int regmap_sdw_config_check(const struct regmap_config *config) +{ + /* Register addresses are 32 bits wide */ + if (config->reg_bits != 32) + return -ENOTSUPP; + + if (config->pad_bits != 0) + return -ENOTSUPP; + + /* Only bulk writes are supported not multi-register writes */ + if (config->can_multi_write) + return -ENOTSUPP; + + return 0; +} + +struct regmap *__regmap_init_sdw(struct sdw_slave *sdw, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + int ret; + + ret = regmap_sdw_config_check(config); + if (ret) + return ERR_PTR(ret); + + return __regmap_init(&sdw->dev, ®map_sdw, + &sdw->dev, config, lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__regmap_init_sdw); + +struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw, + const struct regmap_config *config, + struct lock_class_key *lock_key, + const char *lock_name) +{ + int ret; + + ret = regmap_sdw_config_check(config); + if (ret) + return ERR_PTR(ret); + + return __devm_regmap_init(&sdw->dev, ®map_sdw, + &sdw->dev, config, lock_key, lock_name); +} +EXPORT_SYMBOL_GPL(__devm_regmap_init_sdw); + +MODULE_DESCRIPTION("regmap SoundWire Module"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1