drm/i915/display/vrr: Disable VRR in modeset disable path

This patch disables the VRR enable and VRR PUSH
bits in the HW during commit modeset disable sequence.

Thsi disable will happen when the port is disabled
or when the userspace sets VRR prop to false and
requests to disable VRR.

v2:
* Use intel_de_rmw (Jani N)

v3:
* Remove rmw (Ville)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Manasi Navare <manasi.d.navare@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122232647.22688-12-manasi.d.navare@intel.com

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

@@ -4060,6 +4060,8 @@ static void intel_ddi_post_disable(struct intel_atomic_state *state,
 
 		intel_disable_pipe(old_crtc_state);
 
+		intel_vrr_disable(old_crtc_state);
+
 		intel_ddi_disable_transcoder_func(old_crtc_state);
 
 		intel_dsc_disable(old_crtc_state);

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

@@ -134,3 +134,16 @@ void intel_vrr_send_push(const struct intel_crtc_state *crtc_state)
 	intel_de_write(dev_priv, TRANS_PUSH(cpu_transcoder),
 		       TRANS_PUSH_EN | TRANS_PUSH_SEND);
 }
+
+void intel_vrr_disable(const struct intel_crtc_state *old_crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	enum transcoder cpu_transcoder = old_crtc_state->cpu_transcoder;
+
+	if (!old_crtc_state->vrr.enable)
+		return;
+
+	intel_de_write(dev_priv, TRANS_VRR_CTL(cpu_transcoder), 0);
+	intel_de_write(dev_priv, TRANS_PUSH(cpu_transcoder), 0);
+}

drivers/gpu/drm/i915/display/intel_vrr.h

@@ -23,5 +23,6 @@ void intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
 void intel_vrr_enable(struct intel_encoder *encoder,
 		      const struct intel_crtc_state *crtc_state);
 void intel_vrr_send_push(const struct intel_crtc_state *crtc_state);
+void intel_vrr_disable(const struct intel_crtc_state *old_crtc_state);
 
 #endif /* __INTEL_VRR_H__ */