[PATCH v3 00/20] drm/atomic: Rework initial state allocation

[Maxime Ripard]

Hi,

This series started from my work on the hardware state readout[1], and
more specifically a discussion with Thomas[2].

This series expands the work that has been merged recently to make
drm_private_obj and drm_private_state allocation a bit more consistent
and ended up creating a new atomic_create_state callback to allocate a
new state with no side effect.

The first patches document the existing behaviour and fix a few
cleanups and typos.

Then, __drm_*_state_reset() helpers are renamed to
__drm_*_state_init() to clarify that they initialize rather than
reset state, and we add the new atomic_create_state callback to
every other DRM object (planes, CRTCs, connectors, colorops).

Next, we leverage those new callbacks to create a new helper,
drm_mode_config_create_initial_state(), to create the initial state
for all the objects of a driver, and update the driver skeleton to
recommend it.

Finally, we convert the tidss driver and the bridge_connector to the
new pattern.

This was tested on a TI SK-AM62, with the tidss driver.

Let me know what you think,
Maxime

1: https://lore.kernel.org/dri-devel/20250902-drm-state-readout-v1-0-14ad5315da3f@xxxxxxxxxx/
2: https://lore.kernel.org/dri-devel/5920ffe5-b6b1-484b-b320-332b9eb9db82@xxxxxxx/

Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
---
Changes in v3:
- Reintroduce state documentation that was dropped by accident
- Change name to drm_mode_config_create_initial_state()
- Don't call drm_mode_config_create_initial_state() in drm_dev_register
  anymore
- Drop __drm_atomic_helper_*_create_state
- Improve documentation and commit messages where necessary
- Collected tags
- Link to v2: https://lore.kernel.org/r/20260320-drm-mode-config-init-v2-0-c63f1134e76c@xxxxxxxxxx

Changes in v2:
- Change the _state_reset function names to _state_init
- Change the colorop too
- Various doc improvements
- Link to v1: https://lore.kernel.org/r/20260310-drm-mode-config-init-v1-0-de7397c8e1cf@xxxxxxxxxx

---
Maxime Ripard (20):
      drm/atomic: Document atomic state lifetime
      drm/colorop: Fix typos in the doc
      drm/atomic: Drop drm_private_obj.state assignment from create_state
      drm/atomic: Expand atomic_create_state expectations for drm_private_obj
      drm/mode-config: Document drm_private_obj exclusion from drm_mode_config_reset()
      drm/colorop: Rename __drm_colorop_state_reset()
      drm/colorop: Create drm_atomic_helper_colorop_create_state()
      drm/atomic-state-helper: Fix __drm_atomic_helper_plane_reset() doc typo
      drm/atomic-state-helper: Rename __drm_atomic_helper_plane_state_reset()
      drm/plane: Add new atomic_create_state callback
      drm/atomic-state-helper: Rename __drm_atomic_helper_crtc_state_reset()
      drm/crtc: Add new atomic_create_state callback
      drm/atomic-state-helper: Rename __drm_atomic_helper_connector_state_reset()
      drm/hdmi: Rename __drm_atomic_helper_connector_hdmi_reset()
      drm/connector: Add new atomic_create_state callback
      drm/mode-config: Create drm_mode_config_create_initial_state()
      drm/drv: Switch skeleton to drm_mode_config_create_initial_state()
      drm/tidss: Switch to drm_mode_config_create_initial_state()
      drm/tidss: Convert to atomic_create_state
      drm/bridge_connector: Convert to atomic_create_state

 Documentation/gpu/drm-kms.rst                      |   6 +
 drivers/gpu/drm/display/drm_bridge_connector.c     |  17 ++-
 drivers/gpu/drm/display/drm_hdmi_state_helper.c    |  13 +-
 drivers/gpu/drm/drm_atomic.c                       |  63 +++++++++
 drivers/gpu/drm/drm_atomic_state_helper.c          | 136 +++++++++++++++---
 drivers/gpu/drm/drm_colorop.c                      |  41 ++++--
 drivers/gpu/drm/drm_drv.c                          |   4 +-
 drivers/gpu/drm/drm_mode_config.c                  | 154 ++++++++++++++++++++-
 drivers/gpu/drm/i915/display/intel_crtc.c          |   2 +-
 drivers/gpu/drm/i915/display/intel_plane.c         |   2 +-
 drivers/gpu/drm/sun4i/sun4i_hdmi_enc.c             |   2 +-
 drivers/gpu/drm/tests/drm_hdmi_state_helper_test.c |   2 +-
 drivers/gpu/drm/tidss/tidss_crtc.c                 |  17 +--
 drivers/gpu/drm/tidss/tidss_drv.c                  |   6 +-
 drivers/gpu/drm/tidss/tidss_plane.c                |   2 +-
 drivers/gpu/drm/vc4/vc4_hdmi.c                     |   2 +-
 include/drm/display/drm_hdmi_state_helper.h        |   4 +-
 include/drm/drm_atomic.h                           |   5 +-
 include/drm/drm_atomic_state_helper.h              |  14 +-
 include/drm/drm_colorop.h                          |   2 +
 include/drm/drm_connector.h                        |  16 +++
 include/drm/drm_crtc.h                             |  16 +++
 include/drm/drm_mode_config.h                      |   1 +
 include/drm/drm_plane.h                            |  16 +++
 24 files changed, 476 insertions(+), 67 deletions(-)
---
base-commit: ea61048876a7137897da26dac49ee234fb38a35a
change-id: 20260310-drm-mode-config-init-1e1f52b745d0

Best regards,
-- 
Maxime Ripard <mripard@xxxxxxxxxx>