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/md/dm-cache-policy.c | 174 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 drivers/md/dm-cache-policy.c (limited to 'drivers/md/dm-cache-policy.c') diff --git a/drivers/md/dm-cache-policy.c b/drivers/md/dm-cache-policy.c new file mode 100644 index 000000000..9330d5748 --- /dev/null +++ b/drivers/md/dm-cache-policy.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2012 Red Hat. All rights reserved. + * + * This file is released under the GPL. + */ + +#include "dm-cache-policy-internal.h" +#include "dm.h" + +#include +#include + +/*----------------------------------------------------------------*/ + +#define DM_MSG_PREFIX "cache-policy" + +static DEFINE_SPINLOCK(register_lock); +static LIST_HEAD(register_list); + +static struct dm_cache_policy_type *__find_policy(const char *name) +{ + struct dm_cache_policy_type *t; + + list_for_each_entry(t, ®ister_list, list) + if (!strcmp(t->name, name)) + return t; + + return NULL; +} + +static struct dm_cache_policy_type *__get_policy_once(const char *name) +{ + struct dm_cache_policy_type *t = __find_policy(name); + + if (t && !try_module_get(t->owner)) { + DMWARN("couldn't get module %s", name); + t = ERR_PTR(-EINVAL); + } + + return t; +} + +static struct dm_cache_policy_type *get_policy_once(const char *name) +{ + struct dm_cache_policy_type *t; + + spin_lock(®ister_lock); + t = __get_policy_once(name); + spin_unlock(®ister_lock); + + return t; +} + +static struct dm_cache_policy_type *get_policy(const char *name) +{ + struct dm_cache_policy_type *t; + + t = get_policy_once(name); + if (IS_ERR(t)) + return NULL; + + if (t) + return t; + + request_module("dm-cache-%s", name); + + t = get_policy_once(name); + if (IS_ERR(t)) + return NULL; + + return t; +} + +static void put_policy(struct dm_cache_policy_type *t) +{ + module_put(t->owner); +} + +int dm_cache_policy_register(struct dm_cache_policy_type *type) +{ + int r; + + /* One size fits all for now */ + if (type->hint_size != 0 && type->hint_size != 4) { + DMWARN("hint size must be 0 or 4 but %llu supplied.", (unsigned long long) type->hint_size); + return -EINVAL; + } + + spin_lock(®ister_lock); + if (__find_policy(type->name)) { + DMWARN("attempt to register policy under duplicate name %s", type->name); + r = -EINVAL; + } else { + list_add(&type->list, ®ister_list); + r = 0; + } + spin_unlock(®ister_lock); + + return r; +} +EXPORT_SYMBOL_GPL(dm_cache_policy_register); + +void dm_cache_policy_unregister(struct dm_cache_policy_type *type) +{ + spin_lock(®ister_lock); + list_del_init(&type->list); + spin_unlock(®ister_lock); +} +EXPORT_SYMBOL_GPL(dm_cache_policy_unregister); + +struct dm_cache_policy *dm_cache_policy_create(const char *name, + dm_cblock_t cache_size, + sector_t origin_size, + sector_t cache_block_size) +{ + struct dm_cache_policy *p = NULL; + struct dm_cache_policy_type *type; + + type = get_policy(name); + if (!type) { + DMWARN("unknown policy type"); + return ERR_PTR(-EINVAL); + } + + p = type->create(cache_size, origin_size, cache_block_size); + if (!p) { + put_policy(type); + return ERR_PTR(-ENOMEM); + } + p->private = type; + + return p; +} +EXPORT_SYMBOL_GPL(dm_cache_policy_create); + +void dm_cache_policy_destroy(struct dm_cache_policy *p) +{ + struct dm_cache_policy_type *t = p->private; + + p->destroy(p); + put_policy(t); +} +EXPORT_SYMBOL_GPL(dm_cache_policy_destroy); + +const char *dm_cache_policy_get_name(struct dm_cache_policy *p) +{ + struct dm_cache_policy_type *t = p->private; + + /* if t->real is set then an alias was used (e.g. "default") */ + if (t->real) + return t->real->name; + + return t->name; +} +EXPORT_SYMBOL_GPL(dm_cache_policy_get_name); + +const unsigned int *dm_cache_policy_get_version(struct dm_cache_policy *p) +{ + struct dm_cache_policy_type *t = p->private; + + return t->version; +} +EXPORT_SYMBOL_GPL(dm_cache_policy_get_version); + +size_t dm_cache_policy_get_hint_size(struct dm_cache_policy *p) +{ + struct dm_cache_policy_type *t = p->private; + + return t->hint_size; +} +EXPORT_SYMBOL_GPL(dm_cache_policy_get_hint_size); + +/*----------------------------------------------------------------*/ -- cgit v1.3.1