[PATCH v5 00/44] Color Pipeline API w/ VKMS

Xaver Hugl xaver.hugl at gmail.com
Thu Aug 29 14:55:06 UTC 2024


Hi,

I have a WIP implementation of this for KWin at
https://invent.kde.org/plasma/kwin/-/commits/work/zamundaaa/drm-colorop.
It maps KWin's color pipeline to the drm one to get (primary plane
only, for now) direct scanout of HDR content on SDR displays while
doing tone mapping (or SDR on HDR, but that's been possible before).
It currently uses the two 1D custom luts and the 3D lut for this; once
I add support for named 1D curves, it should also make use of that and
the matrix. I haven't tested the Intel version yet, but if it can
match the pipeline, it should work the same there.

In testing your amd-color-pipeline-v5 branch I get two crashes in the
kernel though: https://invent.kde.org/-/snippets/3217
The null pointer dereference only happens sometimes, seemingly
randomly, but if I make KWin generate new blobs each frame, I can 100%
reliably reproduce the list_add corruption problem by just opening
glxgears in fullscreen while the color profile of the display is set
to "built in" (which makes it use the 3D LUT for gamut mapping).
Here's a branch that generates the color pipeline each frame and
triggers this: https://invent.kde.org/plasma/kwin/-/commits/work/zamundaaa/drm-colorop-list-add-corruption



Am Mo., 19. Aug. 2024 um 22:57 Uhr schrieb Harry Wentland
<harry.wentland at amd.com>:
>
> This is an RFC set for a color pipeline API, along with implementations
> in VKMS and amdgpu. It is tested with a set of IGT tests that can be
> found at [1]. The IGT tests run a pixel-by-pixel comparison with an
> allowable delta variation as the goal for these transformations is
> perceptual correctness, not complete pixel accuracy.
>
> v5 of this patchset fleshed out documentation for colorops and the
> various defines that are being introduced.
>
> VKMS supports two named transfer function colorops and two matrix
> colorops.
>
> Amdgpu advertises the following pipeline for GPUs with DCN 3 or newer:
>
> 1. 1D Curve EOTF
> 2. 3x4 CTM
> 3. Multiplier
> 4. 1D Curve Inverse EOTF
> 5. 1D LUT
> 6. 3D LUT
> 7. 1D Curve EOTF
> 8. 1D LUT
>
> The supported curves for the 1D Curve type are:
> - sRGB EOTF and its inverse
> - PQ EOTF, scaled to [0.0, 125.0] and its inverse
> - BT.2020/BT.709 OETF and its inverse
>
> Note that the 1st and 5th colorops take the EOTF or Inverse
> OETF while the 3rd colorop takes the Inverse EOTF or OETF.
>
> The 3D LUT is a 17^3 tetrahedrally interpolated LUT but the mechanism
> exists for other drivers to describe their own 3D LUT capability.
>
> This mirrors the color pipeline used by gamescope and presented by
> Melissa Wen, with the exception of the DEGAM LUT, which is not currently
> used. See [1]
> https://indico.freedesktop.org/event/4/contributions/186/attachments/138/218/xdc2023-TheRainbowTreasureMap-MelissaWen.pdf
>
> At this point we're hoping to see gamescope and kwin implementations
> take shape. The existing pipeline should be enough to satisfy the
> gamescope use-cases on the drm_plane.
>
> In order to support YUV we'll need to add COLOR_ENCODING and COLOR_RANGE
> support to the color pipeline. I have sketched these out already but
> don't have it all hooked up yet. This should not hinder adoption of this
> API for gaming use-cases.
>
> We'll also want to advertise IN_FORMATS on a color pipeline as some
> color pipelines won't be able to work for all IN_FORMATS on a plane.
> Again, I have a sketch but no full implementation yet. This is not
> currently required by the AMD color pipeline and could be added after
> the merge of this set.
>
> VKMS patches could still be improved in a few ways, though the
> payoff might be limited and I would rather focus on other work
> at the moment. The most obvious thing to improve would be to
> eliminate the hard-coded LUTs for identity, and sRGB, and replace
> them with fixed-point math instead.
>
> There are plenty of things that I would like to see, but they could
> be added after the merge of this patchset:
>  - COLOR_ENCODING and COLOR_RANGE
>  - IN_FORMATS for a color pipeline
>  - Is it possible to support HW which can't bypass entire pipeline?
>  - Can we do a LOAD / COMMIT model for LUTs (and other properties)?
>  - read-only scaling colorop which defines scaling taps and position
>  - named matrices, for things like converting YUV to RGB
>  - Add custom LUT colorops to VKMS
>
> IGT tests can be found at [1] or on the igt-dev mailing list.
>
> A kernel branch can be found at [2].
>
> I've also rebased Uma and Chaitanya's patches for the Intel color
> pipeline on top of this to show how I envision them to mesh with
> my changes. The relevant branches can be found at [3] for the kernel
> and [4] for IGT. There were some rebase conflicts in i915 and I'm
> not entirely sure I've resolved all of them correctly, but the branch
> compiles and shows my thoughts for the new DRM concepts to support
> Intel's pipeline.
>
> [1] https://gitlab.freedesktop.org/hwentland/igt-gpu-tools/-/tree/amd-color-pipeline-v5
> [2] https://gitlab.freedesktop.org/hwentland/linux/-/tree/amd-color-pipeline-v5
> [3] https://gitlab.freedesktop.org/hwentland/linux/-/tree/amd-intel-color-pipeline-v5
> [4] https://gitlab.freedesktop.org/hwentland/igt-gpu-tools/-/tree/amd-intel-color-pipeline-v5
>
>
> v5:
>  - amdgpu 3D LUT
>  - Don't require BYPASS
>  - update RFC docs and add to TOC tree
>  - add drm_colorop and COLOR_PIPELINE kernel docs (non-RFC)
>  - add amdgpu color pipeline doc
>  - define SIZE property similar to drm_crtc's GAMMA_SIZE
>  - various minor fixes and cleanups
>
> v4:
>  - Add amdgpu color pipeline (WIP)
>  - Don't block setting of deprecated properties, instead pass client cap
>    to atomic check so drivers can ignore these props
>  - Drop IOCTL definitions (Pekka)
>  - Use enum property for colorop TYPE (Pekka)
>  - A few cleanups to the docs (Pekka)
>  - Rework the TYPE enum to name relation to avoid code duplication (Pekka)
>  - Add missing function declarations (Chaitanya Kumar Borah)
>  - Allow setting of NEXT property to NULL in _set_ function (Chaitanya Kumar Borah)
>  - Add helper for creation of pipeline drm_plane property (Pekka)
>  - Always create Bypass pipeline (Pekka)
>  - A bunch of changes to VKMS kunit tests (Pekka)
>  - Fix index in CTM doc (Pekka)
>
> v3:
>  - Abandon IOCTLs and discover colorops as clients iterate the pipeline
>  - Remove need for libdrm
>  - Add color_pipeline client cap and make mutually exclusive with
>    COLOR_RANGE and COLOR_ENCODING properties
>  - add CTM colorop to VKMS
>  - Use include way for kunit testing static functions (Arthur)
>  - Make TYPE a range property
>  - Move enum drm_colorop_type to uapi header
>  - and a bunch of smaller bits that are highlighted in the relevant commit
>    description
>
> v2:
>  - Rebased on drm-misc-next
>  - Introduce a VKMS Kunit so we can test LUT functionality in vkms_composer
>  - Incorporate feedback in color_pipeline.rst doc
>  - Add support for sRGB inverse EOTF
>  - Add 2nd enumerated TF colorop to VKMS
>  - Fix LUTs and some issues with applying LUTs in VKMS
>
> Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> Cc: Pekka Paalanen <pekka.paalanen at collabora.com>
> Cc: Simon Ser <contact at emersion.fr>
> Cc: Harry Wentland <harry.wentland at amd.com>
> Cc: Melissa Wen <mwen at igalia.com>
> Cc: Jonas Ådahl <jadahl at redhat.com>
> Cc: Sebastian Wick <sebastian.wick at redhat.com>
> Cc: Shashank Sharma <shashank.sharma at amd.com>
> Cc: Alexander Goins <agoins at nvidia.com>
> Cc: Joshua Ashton <joshua at froggi.es>
> Cc: Michel Dänzer <mdaenzer at redhat.com>
> Cc: Aleix Pol <aleixpol at kde.org>
> Cc: Xaver Hugl <xaver.hugl at gmail.com>
> Cc: Victoria Brekenfeld <victoria at system76.com>
> Cc: Sima <daniel at ffwll.ch>
> Cc: Uma Shankar <uma.shankar at intel.com>
> Cc: Naseer Ahmed <quic_naseer at quicinc.com>
> Cc: Christopher Braga <quic_cbraga at quicinc.com>
> Cc: Abhinav Kumar <quic_abhinavk at quicinc.com>
> Cc: Arthur Grillo <arthurgrillo at riseup.net>
> Cc: Hector Martin <marcan at marcan.st>
> Cc: Liviu Dudau <Liviu.Dudau at arm.com>
> Cc: Sasha McIntosh <sashamcintosh at google.com>
> Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>
>
> Alex Hung (13):
>   drm/colorop: define a new macro for_each_new_colorop_in_state
>   drm/amd/display: Skip color pipeline initialization for cursor plane
>   drm/amd/display: Add support for sRGB EOTF in DEGAM block
>   drm/amd/display: Add support for sRGB Inverse EOTF in SHAPER block
>   drm/amd/display: Add support for sRGB EOTF in BLND block
>   drm/colorop: Add 1D Curve Custom LUT type
>   drm/amd/display: add shaper and blend colorops for 1D Curve Custom LUT
>   drm/amd/display: add 3x4 matrix colorop
>   drm/colorop: Add mutliplier type
>   drm/amd/display: add multiplier colorop
>   drm/amd/display: Swap matrix and multiplier
>   drm/colorop: Add 3D LUT supports to color pipeline
>   drm/amd/display: add 3D LUT colorop
>
> Harry Wentland (31):
>   drm: Add helper for conversion from signed-magnitude
>   drm/vkms: Round fixp2int conversion in lerp_u16
>   drm/vkms: Add kunit tests for VKMS LUT handling
>   drm/doc/rfc: Describe why prescriptive color pipeline is needed
>   drm/colorop: Introduce new drm_colorop mode object
>   drm/colorop: Add TYPE property
>   drm/colorop: Add 1D Curve subtype
>   Documentation/gpu: document drm_colorop
>   drm/colorop: Add BYPASS property
>   drm/colorop: Add NEXT property
>   drm/colorop: Add atomic state print for drm_colorop
>   drm/plane: Add COLOR PIPELINE property
>   drm/colorop: Add NEXT to colorop state print
>   drm/vkms: Add enumerated 1D curve colorop
>   drm/vkms: Add kunit tests for linear and sRGB LUTs
>   drm/colorop: Introduce DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE
>   drm/colorop: Add 3x4 CTM type
>   drm/vkms: Use s32 for internal color pipeline precision
>   drm/vkms: add 3x4 matrix in color pipeline
>   drm/tests: Add a few tests around drm_fixed.h
>   drm/vkms: Add tests for CTM handling
>   drm/colorop: pass plane_color_pipeline client cap to atomic check
>   drm/amd/display: Ignore deprecated props when plane_color_pipeline set
>   drm/amd/display: Add bypass COLOR PIPELINE
>   drm/colorop: Add PQ 125 EOTF and its inverse
>   drm/amd/display: Enable support for PQ 125 EOTF and Inverse
>   drm/colorop: add BT2020/BT709 OETF and Inverse OETF
>   drm/amd/display: Add support for BT.709 and BT.2020 TFs
>   drm/colorop: Define LUT_1D interpolation
>   drm/colorop: allow non-bypass colorops
>   drm/amd/display: Add AMD color pipeline doc
>
>  Documentation/gpu/drm-kms.rst                 |  15 +
>  Documentation/gpu/rfc/color_pipeline.rst      | 376 ++++++++
>  Documentation/gpu/rfc/index.rst               |   3 +
>  drivers/gpu/drm/Makefile                      |   1 +
>  .../gpu/drm/amd/display/amdgpu_dm/Makefile    |   3 +-
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |   4 +
>  .../amd/display/amdgpu_dm/amdgpu_dm_color.c   | 581 ++++++++++++-
>  .../amd/display/amdgpu_dm/amdgpu_dm_colorop.c | 196 +++++
>  .../amd/display/amdgpu_dm/amdgpu_dm_colorop.h |  36 +
>  .../amd/display/amdgpu_dm/amdgpu_dm_plane.c   |  32 +
>  drivers/gpu/drm/drm_atomic.c                  | 184 +++-
>  drivers/gpu/drm/drm_atomic_helper.c           |  12 +
>  drivers/gpu/drm/drm_atomic_state_helper.c     |   5 +
>  drivers/gpu/drm/drm_atomic_uapi.c             | 175 ++++
>  drivers/gpu/drm/drm_colorop.c                 | 562 ++++++++++++
>  drivers/gpu/drm/drm_ioctl.c                   |   7 +
>  drivers/gpu/drm/drm_mode_config.c             |   7 +
>  drivers/gpu/drm/drm_plane.c                   |  52 ++
>  drivers/gpu/drm/tests/Makefile                |   3 +-
>  drivers/gpu/drm/tests/drm_fixp_test.c         |  69 ++
>  drivers/gpu/drm/vkms/Kconfig                  |   5 +
>  drivers/gpu/drm/vkms/Makefile                 |   4 +-
>  drivers/gpu/drm/vkms/tests/.kunitconfig       |   4 +
>  drivers/gpu/drm/vkms/tests/vkms_color_tests.c | 449 ++++++++++
>  drivers/gpu/drm/vkms/vkms_colorop.c           | 102 +++
>  drivers/gpu/drm/vkms/vkms_composer.c          | 115 ++-
>  drivers/gpu/drm/vkms/vkms_drv.h               |   8 +
>  drivers/gpu/drm/vkms/vkms_luts.c              | 802 ++++++++++++++++++
>  drivers/gpu/drm/vkms/vkms_luts.h              |  12 +
>  drivers/gpu/drm/vkms/vkms_plane.c             |   2 +
>  include/drm/drm_atomic.h                      | 130 +++
>  include/drm/drm_atomic_uapi.h                 |   3 +
>  include/drm/drm_colorop.h                     | 427 ++++++++++
>  include/drm/drm_file.h                        |   7 +
>  include/drm/drm_fixed.h                       |  18 +
>  include/drm/drm_mode_config.h                 |  18 +
>  include/drm/drm_plane.h                       |  19 +
>  include/uapi/drm/amdgpu_drm.h                 |   9 -
>  include/uapi/drm/drm.h                        |  16 +
>  include/uapi/drm/drm_mode.h                   | 156 ++++
>  40 files changed, 4595 insertions(+), 34 deletions(-)
>  create mode 100644 Documentation/gpu/rfc/color_pipeline.rst
>  create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_colorop.c
>  create mode 100644 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_colorop.h
>  create mode 100644 drivers/gpu/drm/drm_colorop.c
>  create mode 100644 drivers/gpu/drm/tests/drm_fixp_test.c
>  create mode 100644 drivers/gpu/drm/vkms/tests/.kunitconfig
>  create mode 100644 drivers/gpu/drm/vkms/tests/vkms_color_tests.c
>  create mode 100644 drivers/gpu/drm/vkms/vkms_colorop.c
>  create mode 100644 drivers/gpu/drm/vkms/vkms_luts.c
>  create mode 100644 drivers/gpu/drm/vkms/vkms_luts.h
>  create mode 100644 include/drm/drm_colorop.h
>
> --
> 2.46.0
>


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