[PATCH 00/28] Enable Pipe writeback

[Dmitry Baryshkov]

On Fri, Jul 25, 2025 at 10:33:41AM +0530, Suraj Kandpal wrote:
> This series aims to enable pipe writeback functionality on
> ADLP where it has been tested. The plan is to slowly accomodate
> all supported hardware after this functionality is tested on them.
> This series also brings change to drm core but not in a drastic way.
> We introduce a helper which lets drivers have their own preallocated
> conenctor keeping the connector in drm_writeback_conenctor blank.
> This lets driver have more control over their connector but still use
> the drm core queues for job creation and signalling. Some new helpers
> have been added to aid drivers so that derivation of drm_connector
> from drm_writeback_connector and vice versa becomes easy for drivers
> that will use this helper since it won't be as straight forward as
> wb_conn->connector anymore. Driver not using these API will not be
> affected in anyways.
> This series enables the triggered captured mode where we need to
> trigger a capture.
> 
> Cc: Harry Wetland <harry.wentland at amd.com>
> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> 
> Suraj Kandpal (28):
>   drm/writeback: Add function that takes preallocated connector
>   drm/writeback: Add a helper function to get writeback connector
>   drm/writeback: Define function to get drm_connector from writeback
>   drm/i915/writeback: Add writeback registers
>   drm/i915/writeback: Add some preliminary writeback definitions
>   drm/i915/writeback: Init writeback connector
>   drm/i915/writeback: Add function for get_writeback_connector
>   drm/i915/writeback: Define the get_connector_from_writeback hook
>   drm/i915/writeback: Add function to get modes
>   drm/i915/writeback: Add hook to check modes
>   drm/i915/writeback: Define encoder->get_hw_state
>   drm/i915/writeback: Fill encoder->get_config
>   drm/i915/writeback: Add private structure for writeback job
>   drm/i915/writeback: Define function for prepare and cleanup hooks
>   drm/i915/writeback: Define compute_config for writeback
>   drm/i915/writeback: Define function for connector function detect
>   drm/i915/writeback: Define function to destroy writeback connector
>   drm/i915/writeback: Add connector atomic check

You are adding hooks one by one. Are you sure that the series is
bisectable? In other words, the driver must work (aka must not crash)
after each commit.

>   drm/i915/writeback: Add the enable sequence from writeback
>   drm/i915/writeback: Add writeback to xe Makefile
>   drm/i915/writeback: Define writeback frame capture function
>   drm/i915/writeback: Configure WD_STRIDE reg
>   drm/i915/writeback: Configure WD_SURF register
>   drm/i915/writeback: Enable writeback interrupts
>   drm/i915/writeback: Initialize writeback encoder.
>   drm/i915/writeback: Define the disable sequence for writeback
>   drm/i915/writeback: Make exception for writeback connector
>   drm/i915/writeback: Modify state verify function
> 
>  drivers/gpu/drm/drm_writeback.c               | 123 +++-
>  drivers/gpu/drm/i915/Makefile                 |   1 +
>  drivers/gpu/drm/i915/display/intel_acpi.c     |   1 +
>  .../drm/i915/display/intel_crtc_state_dump.c  |   2 +-
>  drivers/gpu/drm/i915/display/intel_display.c  | 178 +++--
>  drivers/gpu/drm/i915/display/intel_display.h  |   4 +
>  .../drm/i915/display/intel_display_debugfs.c  |   3 +
>  .../drm/i915/display/intel_display_device.c   |  29 +-
>  .../drm/i915/display/intel_display_device.h   |   2 +-
>  .../gpu/drm/i915/display/intel_display_irq.c  |  10 +
>  .../drm/i915/display/intel_display_limits.h   |   2 +
>  .../drm/i915/display/intel_display_power.c    |   4 +
>  .../drm/i915/display/intel_display_power.h    |   2 +
>  .../gpu/drm/i915/display/intel_display_regs.h |   1 +
>  .../drm/i915/display/intel_display_types.h    |   1 +
>  drivers/gpu/drm/i915/display/intel_dpll_mgr.c |   3 +
>  drivers/gpu/drm/i915/display/intel_opregion.c |   2 +-
>  drivers/gpu/drm/i915/display/intel_pmdemand.c |   3 +
>  drivers/gpu/drm/i915/display/intel_vdsc.c     |   4 +
>  .../gpu/drm/i915/display/intel_writeback.c    | 686 ++++++++++++++++++
>  .../gpu/drm/i915/display/intel_writeback.h    |  23 +
>  .../drm/i915/display/intel_writeback_reg.h    | 142 ++++
>  drivers/gpu/drm/xe/Makefile                   |   1 +
>  include/drm/drm_modeset_helper_vtables.h      |  59 ++
>  include/drm/drm_writeback.h                   |  21 +-
>  25 files changed, 1238 insertions(+), 69 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/display/intel_writeback.c
>  create mode 100644 drivers/gpu/drm/i915/display/intel_writeback.h
>  create mode 100644 drivers/gpu/drm/i915/display/intel_writeback_reg.h
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry