drm/i915: Add helper to modeset a set of pipes

Add intel_modeset_pipes_in_mask_early() to modeset a provided set of
pipes, used in a follow-up patch.

As opposed to intel_modeset_all_pipes() which modesets only the active
pipes - others don't requiring programming the HW - modeset all enabled
pipes in intel_modeset_pipes_in_mask_early() which may need to recompute
their state even if they are not active (that is in the DPMS off state).

While at it add DocBook descriptions for the two exported functions.

v2:
- Add a flag controlling if active planes are force updated as well.
- Add DockBook descriptions.
v3:
- For clarity use _early/_late suffixes for the exported functions
  instead of the update_active_planes parameter. (Ville)
v4:
- In intel_modeset_pipes_in_mask_early() update only the crtc
  flags relevant to the early phase. (Ville)
- Rename intel_modeset_all_pipes() in a separate patch.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230921195159.2646027-7-imre.deak@intel.com

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

@@ -5458,16 +5458,90 @@ intel_verify_planes(struct intel_atomic_state *state)
 			     plane_state->uapi.visible);
 }
 
+static int intel_modeset_pipe(struct intel_atomic_state *state,
+			      struct intel_crtc_state *crtc_state,
+			      const char *reason)
+{
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
+	int ret;
+
+	drm_dbg_kms(&i915->drm, "[CRTC:%d:%s] Full modeset due to %s\n",
+		    crtc->base.base.id, crtc->base.name, reason);
+
+	ret = drm_atomic_add_affected_connectors(&state->base,
+						 &crtc->base);
+	if (ret)
+		return ret;
+
+	ret = intel_dp_mst_add_topology_state_for_crtc(state, crtc);
+	if (ret)
+		return ret;
+
+	ret = intel_atomic_add_affected_planes(state, crtc);
+	if (ret)
+		return ret;
+
+	crtc_state->uapi.mode_changed = true;
+
+	return 0;
+}
+
+/**
+ * intel_modeset_pipes_in_mask_early - force a full modeset on a set of pipes
+ * @state: intel atomic state
+ * @reason: the reason for the full modeset
+ * @mask: mask of pipes to modeset
+ *
+ * Add pipes in @mask to @state and force a full modeset on the enabled ones
+ * due to the description in @reason.
+ * This function can be called only before new plane states are computed.
+ *
+ * Returns 0 in case of success, negative error code otherwise.
+ */
+int intel_modeset_pipes_in_mask_early(struct intel_atomic_state *state,
+				      const char *reason, u8 mask)
+{
+	struct drm_i915_private *i915 = to_i915(state->base.dev);
+	struct intel_crtc *crtc;
+
+	for_each_intel_crtc_in_pipe_mask(&i915->drm, crtc, mask) {
+		struct intel_crtc_state *crtc_state;
+		int ret;
+
+		crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
+		if (IS_ERR(crtc_state))
+			return PTR_ERR(crtc_state);
+
+		if (!crtc_state->hw.enable ||
+		    intel_crtc_needs_modeset(crtc_state))
+			continue;
+
+		ret = intel_modeset_pipe(state, crtc_state, reason);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * intel_modeset_all_pipes - force a full modeset on all pipes
+ * @state: intel atomic state
+ * @reason: the reason for the full modeset
+ *
+ * Add all pipes to @state and force a full modeset on the active ones due to
+ * the description in @reason.
+ * This function can be called only after new plane states are computed already.
+ *
+ * Returns 0 in case of success, negative error code otherwise.
+ */
 int intel_modeset_all_pipes(struct intel_atomic_state *state,
 			    const char *reason)
 {
 	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
 	struct intel_crtc *crtc;
 
-	/*
-	 * Add all pipes to the state, and force
-	 * a modeset on all the active ones.
-	 */
 	for_each_intel_crtc(&dev_priv->drm, crtc) {
 		struct intel_crtc_state *crtc_state;
 		int ret;
@@ -5480,27 +5554,13 @@ int intel_modeset_all_pipes(struct intel_atomic_state *state,
 		    intel_crtc_needs_modeset(crtc_state))
 			continue;
 
-		drm_dbg_kms(&dev_priv->drm, "[CRTC:%d:%s] Full modeset due to %s\n",
-			    crtc->base.base.id, crtc->base.name, reason);
+		ret = intel_modeset_pipe(state, crtc_state, reason);
+		if (ret)
+			return ret;
 
-		crtc_state->uapi.mode_changed = true;
 		crtc_state->update_pipe = false;
 		crtc_state->update_m_n = false;
 		crtc_state->update_lrr = false;
-
-		ret = drm_atomic_add_affected_connectors(&state->base,
-							 &crtc->base);
-		if (ret)
-			return ret;
-
-		ret = intel_dp_mst_add_topology_state_for_crtc(state, crtc);
-		if (ret)
-			return ret;
-
-		ret = intel_atomic_add_affected_planes(state, crtc);
-		if (ret)
-			return ret;
-
 		crtc_state->update_planes |= crtc_state->active_planes;
 		crtc_state->async_flip_planes = 0;
 		crtc_state->do_async_flip = false;

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

@@ -511,6 +511,8 @@ void intel_plane_fixup_bitmasks(struct intel_crtc_state *crtc_state);
 void intel_update_watermarks(struct drm_i915_private *i915);
 
 /* modesetting */
+int intel_modeset_pipes_in_mask_early(struct intel_atomic_state *state,
+				      const char *reason, u8 pipe_mask);
 int intel_modeset_all_pipes(struct intel_atomic_state *state,
 			    const char *reason);
 void intel_modeset_get_crtc_power_domains(struct intel_crtc_state *crtc_state,