linux-stable.git/drivers/gpu/drm/amd/display, branch v6.6.156

drm/amd/display: fix BT.2020 YCbCr limited output CSC matrix

2026-08-27T12:29:46+00:00

[ Upstream commit 2f9a5c0f018d4a1586ee892f81f1383219676415 ]

COLOR_SPACE_YCBCR2020_TYPE, which is selected for
COLOR_SPACE_2020_YCBCR_LIMITED color_space, has coefficients that are
incorrect for limited-range output. Its luma and chroma scaling is
full-range so output is too bright and colors are incorrect.

COLOR_SPACE_YCBCR2020_TYPE is closer to a full-range conversion matrix with
incorrect luma offset, so correct the luma offset for full-range and rename
it to COLOR_SPACE_YCBCR2020_FULL_TYPE.

Add COLOR_SPACE_YCBCR2020_LIMITED_TYPE with correct scaling and range for
limited-range output.

Fix related functions so COLOR_SPACE_YCBCR2020_LIMITED_TYPE and
COLOR_SPACE_YCBCR2020_FULL_TYPE are correctly selected based on
dc_color_space.

Derivation of both matrices follows ITU-T H.273:

Table 4, MatrixCoefficients 9, BT.2020-NCL weights:
KR = 0.2627, KB = 0.0593, KG = 1 - KR - KB = 0.6780.

Equations 45-47 in matrix form:
            [  KR             KG             KB            0 ]
M2020_NCL = [ -KR/(2(1-KB))  -KG/(2(1-KB))   1/2           0 ]
            [  1/2           -KG/(2(1-KR))  -KB/(2(1-KR))  0 ]
            [  0              0              0             1 ]

Limited and Full transforms based on equations 30-32 and 36-38 with bit
depth 10, normalized by 1023:

            [ 876/1023   0         0         64/1023  ]
MLimited  = [ 0          896/1023  0         512/1023 ]
            [ 0          0         896/1023  512/1023 ]
            [ 0          0         0         1        ]

            [ 1023/1023  0         0         0        ]
    MFull = [ 0          1023/1023 0         512/1023 ]
            [ 0          0         1023/1023 512/1023 ]
            [ 0          0         0         1        ]

M2020_NCL_Limited = MLimited x M2020_NCL
M2020_NCL_Full    = MFull x M2020_NCL

The upper three rows of M2020_NCL_* are stored in CR, Y, CB order. Each
M2020_NCL_* value is stored as Round(value * 8192) in its 16-bit
two's-complement representation.

Fixes: 973a9c810c78 ("drm/amd/display: Fix COLOR_SPACE_YCBCR2020_TYPE matrix")
Assisted-by: OpenAI-Codex:GPT-5.6-Sol
Tested-by: Igor Paunovic 
Tested-by: Satyajit Roy 
Signed-off-by: Nathan Lucas 
Signed-off-by: Alex Deucher 
(cherry picked from commit 3b906e1dc7e3c9ff9f7940f6828b367a6a9ec73c)
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Fix BT2020 YCbCr limited/full range input

2026-08-27T12:29:46+00:00

[ Upstream commit 07bc2dcbcf403d47d6f305ef7f0d3d489491c5fb ]

[Why]
BT2020 YCbCr input is not handled properly when full range
quantization is used and limited range is not supported at all.

[How]
- Add enums for BT2020 YCbCr limited/full range
- Add limited range CSC matrix

Reviewed-by: Krunoslav Kovac 
Signed-off-by: Ilya Bakoulin 
Signed-off-by: Roman Li 
Tested-by: Robert Mader 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher 
Stable-dep-of: 2f9a5c0f018d ("drm/amd/display: fix BT.2020 YCbCr limited output CSC matrix")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Fix dcn32 DTB DTO update breaking live pixel rate sources

2026-08-03T09:15:33+00:00

commit 76a2db58e95e328007043f54ac3c7336ccbee440 upstream.

dcn32_update_clocks_update_dtb_dto() reprograms the DTB DTO of every
timing generator in the context whenever the DTBCLK reference changes,
passing a zeroed pixel rate and never setting is_hdmi.
dccg32_set_dtbclk_dto() treats a zero pixel rate as a disable request,
and that branch drives PIPE_DTO_SRC_SEL to the DP DTO source. A timing
generator actively scanning out an HDMI stream therefore has its pixel
rate source re-muxed out from under the live raster, and the OTG stops
on the spot.

Two displays where only one runs a 128b/132b link hit this reliably.
is_dtbclk_required() holds the DTBCLK reference high while both are
active, and the moment the 128b/132b stream is torn down (compositor
switch, display disable, hot-unplug) the next safe_to_lower pass drops
the reference to the lowest DPM level and the DTO walk freezes the
surviving screen. On Navi31 the DAL mailbox then goes deaf on the
DISPCLK hard-min that follows the walk in dcn32_update_clocks(),
stranding both SMU mailboxes until reboot.

Set is_hdmi for HDMI and DVI signals so the disable path leaves the
pixel rate source selection on the HDMI path, and pass the real pixel
rate for 128b/132b streams so a reference change rescales their DTO
instead of disabling it.

Fixes: 128c1ca0303f ("drm/amd/display: Update DTBCLK for DCN32")
Signed-off-by: Harry Wentland 
Reviewed-by: Fangzhi Zuo 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher 
[ mschwartz: dcn32 clk_mgr hunk only, as 6.6.y predates the dcn35
  clk_mgr. The rest is HDMI FRL enablement, absent before 7.2, so the
  FRL conditions and the req_audio_dtbclk_khz assignment they guard are
  dropped and the FRL-centric changelog is rewritten. Added the
  pipe_ctx->stream check the new dereferences need. ]
Signed-off-by: Matthew Schwartz 
Signed-off-by: Sasha Levin

drm/amd/display: set new_stream to NULL after release

2026-08-03T09:15:25+00:00

commit 9fa26b9eed6195bf840f39ac183b9a6237548755 upstream.

In dm_update_crtc_state(), the skip_modeset path releases new_stream
via dc_stream_release() but does not set the pointer to NULL.

If a later error (e.g., color management failure) triggers the fail
label, the error path calls dc_stream_release() again on the same
dangling pointer, causing a double release and potential use-after-free.

Fix this by setting new_stream to NULL after the initial release.

Fixes: 9b690ef3c704 ("drm/amd/display: Avoid full modeset when not required")
Signed-off-by: WenTao Liang 
Reviewed-by: George Zhang 
Signed-off-by: Alex Deucher 
(cherry picked from commit 99f3af19073b3ddbfd96e789124cce12c4277b28)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: detect_link_and_local_sink: DP alt mode timeout path leaks prev_sink reference

2026-08-03T09:15:24+00:00

commit a6e14b976be48eebd8769cb5b883a6af7fc5ade1 upstream.

prev_sink is unconditionally retained via dc_sink_retain at function
  entry, but the DP alt mode timeout path inside SIGNAL_TYPE_DISPLAY_PORT
  returns false without releasing prev_sink. All other return paths in the
  function correctly call dc_sink_release(prev_sink), making this the only
  missing cleanup.

Fixes: 54618888d1ea ("drm/amd/display: break down dc_link.c")
Signed-off-by: WenTao Liang 
Reviewed-by: Mario Limonciello (AMD) 
Link: https://patch.msgid.link/20260626124555.36910-1-vulab@iscas.ac.cn
Signed-off-by: Mario Limonciello 
Signed-off-by: Alex Deucher 
(cherry picked from commit 45510cf662dcf46b5d8926d454f338809f107b9d)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Handle struct drm_plane_state.ignore_damage_clips

2026-08-03T09:15:24+00:00

commit ac11060c6d4959e2d4ceada037d2e1e1bfcf6645 upstream.

The mode-setting pipeline can disabled damage clippings for a commit
by setting ignore_damage_clips in struct drm_plane_state. The commit
will then do a full display update.

Test the flag in DCN code and do a full update in DCN code if it has
been set.

Commit 35ed38d58257 ("drm: Allow drivers to indicate the damage helpers
to ignore damage clips") introduced ignore_damage_clips to selectively
ignore damage clipping in certain framebuffer changes. This driver does
not do that, but DRM's damage iterator will soon rely on the flag.
Therefore supporting it here as well make sense for consistency.

Signed-off-by: Thomas Zimmermann 
Fixes: 35ed38d58257 ("drm: Allow drivers to indicate the damage helpers to ignore damage clips")
Cc: Javier Martinez Canillas 
Cc: Thomas Zimmermann 
Cc: Zack Rusin 
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Javier Martinez Canillas 
Reviewed-by: Harry Wentland 
Signed-off-by: Alex Deucher 
(cherry picked from commit a24019f6480fad5c077b5956eed942c8960323d6)
Cc:  # v6.8+
Signed-off-by: Greg Kroah-Hartman

Revert "drm/amd/display: Add missing kdoc for ALLM parameters"

2026-08-03T09:15:17+00:00

This reverts commit bca364c4c75796650e53837fbec174a866141511.

Signed-off-by: Sasha Levin

drm/amd/display: Add missing kdoc for ALLM parameters

2026-07-24T14:03:15+00:00

[ Upstream commit d4c6ec729fb7a8bf8a27b19bd70a1b945ad93dac ]

Add descriptions for the missing parameters for ALLMEnabled and
ALLMValue  to keep the function documentation synchronized with the
function prototype mod_build_hf_vsif_infopacket().

Fixes the below with gcc W=1:
../display/modules/info_packet/info_packet.c:507 function parameter 'ALLMEnabled' not described in 'mod_build_hf_vsif_infopacket'
../display/modules/info_packet/info_packet.c:507 function parameter 'ALLMValue' not described in 'mod_build_hf_vsif_infopacket'

Fixes: 3c2381b92cba ("drm/amd/display: add support for VSIP info packet")
Cc: Roman Li 
Cc: Alex Hung 
Cc: Tom Chung 
Cc: Aurabindo Pillai 
Cc: Wayne Lin 
Cc: Nicholas Kazlauskas 
Cc: Bhawanpreet Lakha 
Signed-off-by: Srinivasan Shanmugam 
Reviewed-by: Alex Hung 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd: Fix set but not used warnings

2026-07-24T14:02:36+00:00

[ Upstream commit 46791d147d3ab3262298478106ef2a52fc7192e2 ]

There are many set but not used warnings under drivers/gpu/drm/amd when
compiling with the latest upstream mainline GCC:

  drivers/gpu/drm/amd/amdgpu/amdgpu_gart.c:305:18: warning: variable ‘p’ set but not used [-Wunused-but-set-variable=]
  drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h:103:26: warning: variable ‘internal_reg_offset’ set but not used [-Wunused-but-set-variable=]
  ...
  drivers/gpu/drm/amd/amdgpu/amdgpu_vcn.h:164:26: warning: variable ‘internal_reg_offset’ set but not used [-Wunused-but-set-variable=]
  ...
  drivers/gpu/drm/amd/amdgpu/../display/dc/dc_dmub_srv.c:445:13: warning: variable ‘pipe_idx’ set but not used [-Wunused-but-set-variable=]
  drivers/gpu/drm/amd/amdgpu/../display/dc/dc_dmub_srv.c:875:21: warning: variable ‘pipe_idx’ set but not used [-Wunused-but-set-variable=]

Remove the variables actually not used or add __maybe_unused attribute for
the variables actually used to fix them, compile tested only.

Signed-off-by: Tiezhu Yang 
Signed-off-by: Alex Deucher 
Signed-off-by: Ron Economos 
Signed-off-by: Sasha Levin

drm/amd/display: Bound VBIOS record-chain walk loops

2026-07-04T11:42:18+00:00

[ Upstream commit ff287df16a1a58aca78b08d1f3ee09fc44da0351 ]

[Why & How]
All record-chain walk loops in bios_parser.c and bios_parser2.c use
for(;;) and only terminate on a 0xFF record_type sentinel or zero
record_size. A malformed VBIOS image missing the terminator record
causes unbounded iteration at probe time, potentially hundreds of
thousands of iterations with record_size=1. In the final iterations
near the BIOS image boundary, struct casts beyond the 2-byte header
validated by GET_IMAGE can also read out of bounds.

Cap all 14 record-chain walk loops to BIOS_MAX_NUM_RECORD (256)
iterations. The atombios.h defines up to 22 distinct record types
and atomfirmware.h has 13. Assuming an average of less than 10
records per type (which is reasonable since most are connector-
based) 256 is a generous upper bound.

Fixes: 4562236b3bc0 ("drm/amd/dc: Add dc display driver (v2)")
Assisted-by: Copilot:claude-opus-4.6 Mythos
Reviewed-by: Alex Hung 
Signed-off-by: Harry Wentland 
Signed-off-by: Ray Wu 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher 
(cherry picked from commit 95700a3d660287ed657d6892f7be9ffc0e294a93)
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin