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) --- arch/powerpc/sysdev/dart.h | 64 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 arch/powerpc/sysdev/dart.h (limited to 'arch/powerpc/sysdev/dart.h') diff --git a/arch/powerpc/sysdev/dart.h b/arch/powerpc/sysdev/dart.h new file mode 100644 index 000000000..7f5df03d3 --- /dev/null +++ b/arch/powerpc/sysdev/dart.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2004 Olof Johansson , IBM Corporation + */ + +#ifndef _POWERPC_SYSDEV_DART_H +#define _POWERPC_SYSDEV_DART_H + + +/* Offset from base to control register */ +#define DART_CNTL 0 + +/* Offset from base to exception register */ +#define DART_EXCP_U3 0x10 +/* Offset from base to TLB tag registers */ +#define DART_TAGS_U3 0x1000 + +/* U4 registers */ +#define DART_BASE_U4 0x10 +#define DART_SIZE_U4 0x20 +#define DART_EXCP_U4 0x30 +#define DART_TAGS_U4 0x1000 + +/* Control Register fields */ + +/* U3 registers */ +#define DART_CNTL_U3_BASE_MASK 0xfffff +#define DART_CNTL_U3_BASE_SHIFT 12 +#define DART_CNTL_U3_FLUSHTLB 0x400 +#define DART_CNTL_U3_ENABLE 0x200 +#define DART_CNTL_U3_SIZE_MASK 0x1ff +#define DART_CNTL_U3_SIZE_SHIFT 0 + +/* U4 registers */ +#define DART_BASE_U4_BASE_MASK 0xffffff +#define DART_BASE_U4_BASE_SHIFT 0 +#define DART_CNTL_U4_ENABLE 0x80000000 +#define DART_CNTL_U4_IONE 0x40000000 +#define DART_CNTL_U4_FLUSHTLB 0x20000000 +#define DART_CNTL_U4_IDLE 0x10000000 +#define DART_CNTL_U4_PAR_EN 0x08000000 +#define DART_CNTL_U4_IONE_MASK 0x07ffffff +#define DART_SIZE_U4_SIZE_MASK 0x1fff +#define DART_SIZE_U4_SIZE_SHIFT 0 + +#define DART_REG(r) (dart + ((r) >> 2)) +#define DART_IN(r) (in_be32(DART_REG(r))) +#define DART_OUT(r,v) (out_be32(DART_REG(r), (v))) + + +/* size of table in pages */ + + +/* DART table fields */ + +#define DARTMAP_VALID 0x80000000 +#define DARTMAP_RPNMASK 0x00ffffff + + +#define DART_PAGE_SHIFT 12 +#define DART_PAGE_SIZE (1 << DART_PAGE_SHIFT) + + +#endif /* _POWERPC_SYSDEV_DART_H */ -- cgit v1.3.1