drm/i915/wm: add .get_hw_state to watermark funcs

Get rid of the if ladder in intel_modeset_setup_hw_state() and hide a
number of functions by adding a .get_hw_state() hook to watermark
functions. At least for now, combine the platform specific sanitization
to the hw state readouts on the relevant platforms instead of adding a
separate hook for that.

There's a functional change on PCH split platforms: If i9xx_wm_init()
fails to read plane latency and chooses the nop functions,
ilk_wm_get_hw_state() won't get called for readout. Add the
ilk_init_lp_watermarks() call on that path which now won't be called in
.get_hw_state(), as it looks like the only thing that could make a
difference.

v2:
- Add missing static (kernel test robot)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/6da32831e40606cc8b90491b83196917f2ce36ab.1676317696.git.jani.nikula@intel.com

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_wm.h b/drivers/gpu/drm/i915/display/intel_wm.h
index 2b62f818099e..dc582967a25e 100644
--- a/drivers/gpu/drm/i915/display/intel_wm.h
+++ b/drivers/gpu/drm/i915/display/intel_wm.h
@@ -26,6 +26,7 @@ void intel_atomic_update_watermarks(struct intel_atomic_state *state,
 void intel_optimize_watermarks(struct intel_atomic_state *state,
 			       struct intel_crtc *crtc);
 int intel_compute_global_watermarks(struct intel_atomic_state *state);
+void intel_wm_get_hw_state(struct drm_i915_private *i915);
 bool intel_wm_plane_visible(const struct intel_crtc_state *crtc_state,
 			    const struct intel_plane_state *plane_state);
 void intel_print_wm_latency(struct drm_i915_private *i915,