drm/i915/skl: SKL Watermark Computation
This patch implements the watermark algorithm and its necessary
functions. Two function pointers skl_update_wm and
skl_update_sprite_wm are provided. The skl_update_wm will update
the watermarks for the crtc provided as an argument and then
checks for change in DDB allocation for other active pipes and
recomputes the watermarks for those Pipes and planes as well.
Finally it does the register programming for all dirty pipes.
The trigger of the Watermark double buffer registers will have
to be once the plane configurations are done by the caller.
v2: fixed the divide-by-0 error in the results computation func.
Also reworked the PLANE_WM register values computation func to
make it more compact. Incorporated all other review comments
from Damien.
v3: Changed the skl_compute_plane_wm function to now return success
or failure. Also the result blocks and lines are computed here
instead of in skl_compute_wm_results function.
v4: Adjust skl_ddb_alloc_changed() to the new planes/cursor split
(Damien)
v5: Reworked the affected functions to implement new plane/cursor
split.
v6: Rework the logic that triggers the DDB allocation and WM computation
of skl_update_other_pipe_wm() to not depend on non-computed DDB
values.
Always give a valid cursor_width (at boot it's 0) to keep the
invariant that we consider the cursor plane always enabled.
Otherwise we end up dividing by 0 in skl_compute_plane_wm()
(Damien Lespiau)
v7: Spell out allocation
skl_ddb_ functions should have the ddb as first argument
Make the skl_ddb_alloc_changed() parameters const
(Damien)
v8: Rebase on top of the crtc->primary changes
v9: Split the staging results structure to not exceed the 1Kb stack
allocation in skl_update_wm()
v10: Make skl_pipe_pixel_rate() take a pointer to the pipe config
Add a comment about overflow considerations for skl_wm_method1()
Various additions of const
Various use of sizeof(variable) instead of sizeof(type)
Various move of variable definitons to a narrower scope
Zero initialize some stack allocated structures to make sure we
don't have garbage in case we don't write all the values
(Ville)
v11: Remove non-necessary default number of blocks/lines when the plane
is disabled (Ville)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Pradeep Bhat <pradeep.bhat@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2 files changed