drm/i915/display: tie DMC wakelock to DC5/6 state transitions

We only need DMC wakelocks when we allow DC5 and DC6 states.  Add the
calls to enable and disable DMC wakelock accordingly.

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240412094148.808179-5-luciano.coelho@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_display_power_well.c

@@ -17,6 +17,7 @@
 #include "intel_dkl_phy.h"
 #include "intel_dkl_phy_regs.h"
 #include "intel_dmc.h"
+#include "intel_dmc_wl.h"
 #include "intel_dp_aux_regs.h"
 #include "intel_dpio_phy.h"
 #include "intel_dpll.h"
@@ -821,6 +822,8 @@ void gen9_enable_dc5(struct drm_i915_private *dev_priv)
 		intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1,
 			     0, SKL_SELECT_ALTERNATE_DC_EXIT);
 
+	intel_dmc_wl_enable(dev_priv);
+
 	gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC5);
 }
 
@@ -850,6 +853,8 @@ void skl_enable_dc6(struct drm_i915_private *dev_priv)
 		intel_de_rmw(dev_priv, GEN8_CHICKEN_DCPR_1,
 			     0, SKL_SELECT_ALTERNATE_DC_EXIT);
 
+	intel_dmc_wl_enable(dev_priv);
+
 	gen9_set_dc_state(dev_priv, DC_STATE_EN_UPTO_DC6);
 }
 
@@ -970,6 +975,8 @@ void gen9_disable_dc_states(struct drm_i915_private *dev_priv)
 	if (!HAS_DISPLAY(dev_priv))
 		return;
 
+	intel_dmc_wl_disable(dev_priv);
+
 	intel_cdclk_get_cdclk(dev_priv, &cdclk_config);
 	/* Can't read out voltage_level so can't use intel_cdclk_changed() */
 	drm_WARN_ON(&dev_priv->drm,

drivers/gpu/drm/i915/display/intel_dmc.c

@@ -552,6 +552,8 @@ void intel_dmc_disable_program(struct drm_i915_private *i915)
 	pipedmc_clock_gating_wa(i915, true);
 	disable_all_event_handlers(i915);
 	pipedmc_clock_gating_wa(i915, false);
+
+	intel_dmc_wl_disable(i915);
 }
 
 void assert_dmc_loaded(struct drm_i915_private *i915)
@@ -1081,6 +1083,8 @@ void intel_dmc_suspend(struct drm_i915_private *i915)
 	if (dmc)
 		flush_work(&dmc->work);
 
+	intel_dmc_wl_disable(i915);
+
 	/* Drop the reference held in case DMC isn't loaded. */
 	if (!intel_dmc_has_payload(i915))
 		intel_dmc_runtime_pm_put(i915);