[v5,00/19] drm/atomic: Rework initial state allocation

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@kernel.org/
2: https://lore.kernel.org/dri-devel/5920ffe5-b6b1-484b-b320-332b9eb9db82@suse.de/

Signed-off-by: Maxime Ripard <mripard@kernel.org>
---
Changes in v5:
- Address sashiko reviews
- Improve the docs
- Fix drmm_connector_hdmi_init
- Drop drm/tidss: Switch to drm_mode_config_create_initial_state since
  not all possible bridges would have been converted to create_state 
- Link to v4: https://lore.kernel.org/r/20260512-drm-mode-config-init-v4-0-591dfdcc1bf9@kernel.org

Changes in v4:
- Rebased on current drm-misc-next
- Update drm_atomic_state to drm_atomic_commit
- Various doc impromvements
- Don't call drm_crtc_vblank_reset in create_state
- Prevent mem leak if states already have a state when
  drm_mode_config_reset or _create_initial_state are called
- Link to v3: https://lore.kernel.org/r/20260424-drm-mode-config-init-v3-0-8b68d9db0d8b@kernel.org

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@kernel.org

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@kernel.org

---
Maxime Ripard (19):
      drm/atomic: Document atomic commit 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: 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    |  15 +-
 drivers/gpu/drm/drm_atomic.c                       |  67 ++++++++
 drivers/gpu/drm/drm_atomic_state_helper.c          | 114 ++++++++++---
 drivers/gpu/drm/drm_colorop.c                      |  41 ++++-
 drivers/gpu/drm/drm_connector.c                    |  10 +-
 drivers/gpu/drm/drm_drv.c                          |   4 +-
 drivers/gpu/drm/drm_mode_config.c                  | 189 ++++++++++++++++++++-
 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_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              |  12 +-
 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, 496 insertions(+), 68 deletions(-)
---
base-commit: 69c95e4c529297c25503e60acba757fba24fdc95
change-id: 20260310-drm-mode-config-init-1e1f52b745d0

Best regards,
  

I only had comments on the writing. Looks good otherwise.

Best regards
Thomas

Am 19.05.26 um 11:01 schrieb 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@kernel.org/
> 2: https://lore.kernel.org/dri-devel/5920ffe5-b6b1-484b-b320-332b9eb9db82@suse.de/
>
> Signed-off-by: Maxime Ripard <mripard@kernel.org>
> ---
> Changes in v5:
> - Address sashiko reviews
> - Improve the docs
> - Fix drmm_connector_hdmi_init
> - Drop drm/tidss: Switch to drm_mode_config_create_initial_state since
>    not all possible bridges would have been converted to create_state
> - Link to v4: https://lore.kernel.org/r/20260512-drm-mode-config-init-v4-0-591dfdcc1bf9@kernel.org
>
> Changes in v4:
> - Rebased on current drm-misc-next
> - Update drm_atomic_state to drm_atomic_commit
> - Various doc impromvements
> - Don't call drm_crtc_vblank_reset in create_state
> - Prevent mem leak if states already have a state when
>    drm_mode_config_reset or _create_initial_state are called
> - Link to v3: https://lore.kernel.org/r/20260424-drm-mode-config-init-v3-0-8b68d9db0d8b@kernel.org
>
> 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@kernel.org
>
> 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@kernel.org
>
> ---
> Maxime Ripard (19):
>        drm/atomic: Document atomic commit 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: 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    |  15 +-
>   drivers/gpu/drm/drm_atomic.c                       |  67 ++++++++
>   drivers/gpu/drm/drm_atomic_state_helper.c          | 114 ++++++++++---
>   drivers/gpu/drm/drm_colorop.c                      |  41 ++++-
>   drivers/gpu/drm/drm_connector.c                    |  10 +-
>   drivers/gpu/drm/drm_drv.c                          |   4 +-
>   drivers/gpu/drm/drm_mode_config.c                  | 189 ++++++++++++++++++++-
>   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_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              |  12 +-
>   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, 496 insertions(+), 68 deletions(-)
> ---
> base-commit: 69c95e4c529297c25503e60acba757fba24fdc95
> change-id: 20260310-drm-mode-config-init-1e1f52b745d0
>
> Best regards,