drm/i915: split intel_modeset_init() to pre/post irq install

Split inte_modeset_init() to parts before and after irq install, to
facilitate further cleanup. The error paths are a mess, otherwise no
functional changes.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200224120828.22105-1-jani.nikula@intel.com

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

@@ -17778,11 +17778,9 @@ static void plane_config_fini(struct intel_initial_plane_config *plane_config)
 		i915_vma_put(plane_config->vma);
 }
 
-int intel_modeset_init(struct drm_i915_private *i915)
+/* part #1: call before irq install */
+int intel_modeset_init_noirq(struct drm_i915_private *i915)
 {
-	struct drm_device *dev = &i915->drm;
-	enum pipe pipe;
-	struct intel_crtc *crtc;
 	int ret;
 
 	i915->modeset_wq = alloc_ordered_workqueue("i915_modeset", 0);
@@ -17807,6 +17805,17 @@ int intel_modeset_init(struct drm_i915_private *i915)
 
 	intel_fbc_init(i915);
 
+	return 0;
+}
+
+/* part #2: call after irq install */
+int intel_modeset_init(struct drm_i915_private *i915)
+{
+	struct drm_device *dev = &i915->drm;
+	enum pipe pipe;
+	struct intel_crtc *crtc;
+	int ret;
+
 	intel_init_pm(i915);
 
 	intel_panel_sanitize_ssc(i915);

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

@@ -614,6 +614,7 @@ intel_format_info_is_yuv_semiplanar(const struct drm_format_info *info,
 
 /* modesetting */
 void intel_modeset_init_hw(struct drm_i915_private *i915);
+int intel_modeset_init_noirq(struct drm_i915_private *i915);
 int intel_modeset_init(struct drm_i915_private *i915);
 void intel_modeset_driver_remove(struct drm_i915_private *i915);
 void intel_modeset_driver_remove_noirq(struct drm_i915_private *i915);

drivers/gpu/drm/i915/i915_drv.c

@@ -238,8 +238,14 @@ static int i915_driver_modeset_probe_noirq(struct drm_i915_private *i915)
 
 	intel_csr_ucode_init(i915);
 
+	ret = intel_modeset_init_noirq(i915);
+	if (ret)
+		goto cleanup_vga_client;
+
 	return 0;
 
+cleanup_vga_client:
+	intel_vga_unregister(i915);
 out:
 	return ret;
 }