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/regcache-flat.c | 175 ++++++++++++++++++++++++++++++++++++ 1 file changed, 175 insertions(+) create mode 100644 drivers/base/regmap/regcache-flat.c (limited to 'drivers/base/regmap/regcache-flat.c') diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c new file mode 100644 index 000000000..be8497fd2 --- /dev/null +++ b/drivers/base/regmap/regcache-flat.c @@ -0,0 +1,175 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Register cache access API - flat caching support +// +// Copyright 2012 Wolfson Microelectronics plc +// +// Author: Mark Brown + +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +static inline unsigned int regcache_flat_get_index(const struct regmap *map, + unsigned int reg) +{ + return regcache_get_index_by_order(map, reg); +} + +struct regcache_flat_data { + unsigned long *valid; + unsigned int data[]; +}; + +static int regcache_flat_init(struct regmap *map) +{ + unsigned int cache_size; + struct regcache_flat_data *cache; + + if (!map || map->reg_stride_order < 0 || !map->max_register_is_set) + return -EINVAL; + + cache_size = regcache_flat_get_index(map, map->max_register) + 1; + cache = kzalloc_flex(*cache, data, cache_size, map->alloc_flags); + if (!cache) + return -ENOMEM; + + cache->valid = bitmap_zalloc(cache_size, map->alloc_flags); + if (!cache->valid) + goto err_free; + + map->cache = cache; + + return 0; + +err_free: + kfree(cache); + return -ENOMEM; +} + +static void regcache_flat_exit(struct regmap *map) +{ + struct regcache_flat_data *cache = map->cache; + + if (cache) + bitmap_free(cache->valid); + + kfree(cache); + map->cache = NULL; +} + +static int regcache_flat_populate(struct regmap *map) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int i; + + for (i = 0; i < map->num_reg_defaults; i++) { + unsigned int reg = map->reg_defaults[i].reg; + unsigned int index = regcache_flat_get_index(map, reg); + + cache->data[index] = map->reg_defaults[i].def; + __set_bit(index, cache->valid); + } + + if (map->reg_default_cb) { + dev_dbg(map->dev, + "Populating regcache_flat using reg_default_cb callback\n"); + + for (i = 0; i <= map->max_register; i += map->reg_stride) { + unsigned int index = regcache_flat_get_index(map, i); + unsigned int value; + + if (test_bit(index, cache->valid)) + continue; + + if (map->reg_default_cb(map->dev, i, &value)) + continue; + + cache->data[index] = value; + __set_bit(index, cache->valid); + } + } + + return 0; +} + +static int regcache_flat_read(struct regmap *map, + unsigned int reg, unsigned int *value) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); + + /* legacy behavior: ignore validity, but warn the user */ + if (unlikely(!test_bit(index, cache->valid))) + dev_warn_once(map->dev, + "using zero-initialized flat cache, this may cause unexpected behavior"); + + *value = cache->data[index]; + + return 0; +} + +static int regcache_flat_sparse_read(struct regmap *map, + unsigned int reg, unsigned int *value) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); + + if (unlikely(!test_bit(index, cache->valid))) + return -ENOENT; + + *value = cache->data[index]; + + return 0; +} + +static int regcache_flat_write(struct regmap *map, unsigned int reg, + unsigned int value) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int index = regcache_flat_get_index(map, reg); + + cache->data[index] = value; + __set_bit(index, cache->valid); + + return 0; +} + +static int regcache_flat_drop(struct regmap *map, unsigned int min, + unsigned int max) +{ + struct regcache_flat_data *cache = map->cache; + unsigned int bitmap_min = regcache_flat_get_index(map, min); + unsigned int bitmap_max = regcache_flat_get_index(map, max); + + bitmap_clear(cache->valid, bitmap_min, bitmap_max + 1 - bitmap_min); + + return 0; +} + +struct regcache_ops regcache_flat_ops = { + .type = REGCACHE_FLAT, + .name = "flat", + .init = regcache_flat_init, + .exit = regcache_flat_exit, + .populate = regcache_flat_populate, + .read = regcache_flat_read, + .write = regcache_flat_write, +}; + +struct regcache_ops regcache_flat_sparse_ops = { + .type = REGCACHE_FLAT_S, + .name = "flat-sparse", + .init = regcache_flat_init, + .exit = regcache_flat_exit, + .populate = regcache_flat_populate, + .read = regcache_flat_sparse_read, + .write = regcache_flat_write, + .drop = regcache_flat_drop, +}; -- cgit v1.3.1