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) --- include/net/psample.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 include/net/psample.h (limited to 'include/net/psample.h') diff --git a/include/net/psample.h b/include/net/psample.h new file mode 100644 index 000000000..5071b5fc2 --- /dev/null +++ b/include/net/psample.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_PSAMPLE_H +#define __NET_PSAMPLE_H + +#include +#include + +struct psample_group { + struct list_head list; + struct net *net; + u32 group_num; + u32 refcount; + u32 seq; + struct rcu_head rcu; +}; + +struct psample_metadata { + u32 trunc_size; + int in_ifindex; + int out_ifindex; + u16 out_tc; + u64 out_tc_occ; /* bytes */ + u64 latency; /* nanoseconds */ + u8 out_tc_valid:1, + out_tc_occ_valid:1, + latency_valid:1, + rate_as_probability:1, + unused:4; + const u8 *user_cookie; + u32 user_cookie_len; +}; + +struct psample_group *psample_group_get(struct net *net, u32 group_num); +void psample_group_take(struct psample_group *group); +void psample_group_put(struct psample_group *group); + +struct sk_buff; + +#if IS_ENABLED(CONFIG_PSAMPLE) + +void psample_sample_packet(struct psample_group *group, + const struct sk_buff *skb, u32 sample_rate, + const struct psample_metadata *md); + +#else + +static inline void psample_sample_packet(struct psample_group *group, + const struct sk_buff *skb, + u32 sample_rate, + const struct psample_metadata *md) +{ +} + +#endif + +#endif /* __NET_PSAMPLE_H */ -- cgit v1.3.1