[v6,00/14] drm/msm/dpu: Add Concurrent Writeback Support for DPU 10.x+

Message

Jessica Zhang Feb. 15, 2025, 12:14 a.m. UTC

DPU supports a single writeback session running concurrently with primary
display when the CWB mux is configured properly. This series enables
clone mode for DPU driver and adds support for programming the CWB mux
in cases where the hardware has dedicated CWB pingpong blocks. Currently,
the CWB hardware blocks have only been added to the SM8650
hardware catalog and only DSI has been exposed as a possible_clone of WB.

This changes are split into two parts:

The first part of the series will pull in Dmitry's patches to refactor
the DPU resource manager to be based off of CRTC instead of encoder.
This includes some changes (noted in the relevant commits) by me and
Abhinav to fix some issues with getting the global state and refactoring
the CDM allocation to work with Dmitry's changes.

The second part of the series will add support for CWB by doing the
following:

1) Add the CWB mux to the hardware catalog and clarify the pingpong
   block index enum to specifiy which pingpong blocks are dedicated to
   CWB only and which ones are general use pingpong blocks
2) Add support for configuring the CWB mux via dpu_hw_cwb ops
3) Add pending flush support for CWB
4) Add support for validating clone mode in the DPU CRTC and setting up
   CWB within the encoder
5) Adjust the encoder trigger flush, trigger start, and kickoff order to
   accomodate clone mode
6) Adjust when the frame done timer is started for clone mode
7) Define the possible clones for DPU encoders so that WB encoders can
   be cloned by non-WB encoders

The feature was tested on SM8650 using IGT's kms_writeback test with the
following change [1] and dumping the writeback framebuffer when in clone
mode. I haven't gotten the chance to test it on DP yet, but I've
validated both single and dual LM on DSI.

To test CWB with IGT, you'll need to apply this series [1] and run the
following command to dump the writeback buffer:

IGT_FRAME_DUMP_PATH=<dump path> FRAME_PNG_FILE_NAME=<file name> \
./build/tests/kms_writeback -d [--run-subtest dump-valid-clones] \

You can also do CRC validation by running this command:

./build/tests/kms_writeback [--run-subtest dump-valid-clones]

Note: When running IGT on SC7180, you will also need this IGT fix [2] to
prevent IGT tests from failing after runningt kms_color@ctm-* tests.

[1] https://patchwork.freedesktop.org/series/137933/
[2] https://patchwork.freedesktop.org/series/144911/

---
Changes in v6:
- Don't return early from dpu_crtc_assign_resources() if encoder mask is
  0
- Dropped duplicate initialization and unnecessary clearing of the crtc
  state
- Fixed b4 dependencies list (Dmitry)
- cdm_requested -> num_cdm (Dmitry)
- Added comment doc on why we can use the RM array index to enforce the
  CWB odd/even rule (Dmitry)
- Link to v5: https://lore.kernel.org/r/[e-mail]

Changes in v5:
- Rebased onto MSM modeset fixes series (Dmitry)
- Reordered RM refactor patches to prevent breaking CI and to avoid
  breaking when partially applied (Dmitry)
- Switch CWB resource reservation to reserve CWB mux first (Dmitry)
- Reworded commit messages to be clearer (Dmitry)
- Change CDM check to fail only if both DP and WB outputs are
  requesting the CDM block simultaneously (Dmitry)
- Use helper to grab dsc config in dpu_encoder_update_topology
- Link to v4: https://lore.kernel.org/r/[e-mail]

Changes in v4:
- Rebased onto latest msm-next
- Added kunit tests for framework changes
- Skip valid clone check for encoders that don't have any possible clones set
  (this is to avoid failing kunit tests, specifically the HDMI state helper tests)
- Link to v3: https://lore.kernel.org/r/[e-mail]

Changes in v3:
- Dropped support for CWB on DP connectors for now
- Dropped unnecessary PINGPONG array in *_setup_cwb()
- Add a check to make sure CWB and CDM aren't supported simultaneously
  (Dmitry)
- Document cwb_enabled checks in dpu_crtc_get_topology() (Dmitry)
- Moved implementation of drm_crtc_in_clone_mode() to drm_crtc.c (Jani)
- Dropped duplicate error message for reserving CWB resources (Dmitry)
- Added notes in framework changes about posting a separate series to
  add proper KUnit tests (Maxime)
- Added commit message note addressing Sima's comment on handling
  mode_changed (Dmitry)
- Formatting fixes (Dmitry)
- Added proper kerneldocs (Dmitry)
- Renamed dpu_encoder_helper_get_cwb() -> *_get_cwb_mask() (Dmitry)
- Capitalize all instances of "pingpong" in comments (Dmitry)
- Link to v2: https://lore.kernel.org/r/[e-mail]

Changes in v2:
- Moved CWB hardware programming to its own dpu_hw_cwb abstraction
  (Dmitry)
- Reserve and get assigned CWB muxes using RM API and KMS global state
  (Dmitry)
- Dropped requirement to have only one CWB session at a time
- Moved valid clone mode check to DRM framework (Dmitry and Ville)
- Switch to default CWB tap point to LM as the DSPP
- Dropped printing clone mode status in atomic state (Dmitry)
- Call dpu_vbif_clear_errors() before dpu_encoder_kickoff() (Dmitry)
- Squashed setup_input_ctrl() and setup_input_mode() into a single
  dpu_hw_cwb op (Dmitry)
- Moved function comment docs to correct place and fixed wording of
  comments/commit messages (Dmitry)
- Grabbed old CRTC state using proper drm_atomic_state API in
  dpu_crtc_atomic_check() (Dmitry)
- Split HW catalog changes of adding the CWB mux block and changing the
  dedicated CWB pingpong indices into 2 separate commits (Dmitry)
- Moved clearing the dpu_crtc_state.num_mixers to "drm/msm/dpu: fill
  CRTC resources in dpu_crtc.c" (Dmitry)
- Fixed alignment and other formatting issues (Dmitry)
- Link to v1: https://lore.kernel.org/r/[e-mail]

---
Dmitry Baryshkov (3):
      drm/msm/dpu: fill CRTC resources in dpu_crtc.c
      drm/msm/dpu: move resource allocation to CRTC
      drm/msm/dpu: switch RM to use crtc_id rather than enc_id for allocation

Jessica Zhang (11):
      drm/msm/dpu: Add CWB to msm_display_topology
      drm/msm/dpu: Require modeset if clone mode status changes
      drm/msm/dpu: Fail atomic_check if multiple outputs request CDM block
      drm/msm/dpu: Reserve resources for CWB
      drm/msm/dpu: Configure CWB in writeback encoder
      drm/msm/dpu: Support CWB in dpu_hw_ctl
      drm/msm/dpu: Adjust writeback phys encoder setup for CWB
      drm/msm/dpu: Start frame done timer after encoder kickoff
      drm/msm/dpu: Skip trigger flush and start for CWB
      drm/msm/dpu: Reorder encoder kickoff for CWB
      drm/msm/dpu: Set possible clones for all encoders

 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c           | 222 ++++++++++-
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h           |   3 +
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c        | 418 ++++++++++++---------
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h        |  16 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h   |   7 +-
 .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c    |  16 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.c         |  30 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_ctl.h         |  15 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_hw_mdss.h        |   2 +
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c            |  27 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h            |  13 +-
 drivers/gpu/drm/msm/disp/dpu1/dpu_rm.c             | 298 ++++++++++-----
 drivers/gpu/drm/msm/disp/dpu1/dpu_rm.h             |  14 +-
 13 files changed, 753 insertions(+), 328 deletions(-)
---
base-commit: 866e43b945bf98f8e807dfa45eca92f931f3a032
change-id: 20240618-concurrent-wb-97d62387f952
prerequisite-change-id: 20241222-drm-dirty-modeset-88079bd27ae6:v2
prerequisite-patch-id: 0c61aabfcd13651203f476985380cbf4d3c299e6
prerequisite-patch-id: c6026f08011c288fd301676e9fa6f46d0cc1dab7
prerequisite-patch-id: b0cb06d5c88791d6e4755d879ced0d5050aa3cbf
prerequisite-patch-id: fd72ddde9dba0df053113bc505c213961a9760da
prerequisite-change-id: 20250209-dpu-c3fac78fc617:v2
prerequisite-patch-id: c84d2b4b06be06384968429085d1e8ebae23a583
prerequisite-patch-id: fb8ea7b9e7c85fabd27589c6551108382a235002
prerequisite-change-id: 20250211-dither-disable-b77b1e31977f:v1
prerequisite-patch-id: 079e04296212b4b83d51394b5a9b5eea6870d98a

Best regards,