drm/i915: ignore bios output config if not all outputs are on

Both Ville and QA rather immediately complained that with the new
initial_config logic from Jesse not all outputs get enabled. Since the
fbdev emulation pretty much tries to always enable as many outputs as
possible (it even has hotplug handling and all that) fall back if more
outputs could have been enabled.

v2: Fix up my confusion about what enabled means - it's passed from
the fbdev helper, we need to check for a non-zero connector->encoder
link. Spotted by Ville.

v3: Add some debug output as requested by Jesse for debugging fallback
issues.

Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75552Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_fbdev.c

@@ -290,6 +290,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 	int i, j;
 	bool *save_enabled;
 	bool fallback = true;
+	int num_connectors_enabled = 0;
+	int num_connectors_detected = 0;
 
 	/*
 	 * If the user specified any force options, just bail here
@@ -324,6 +326,10 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 
 		fb_conn = fb_helper->connector_info[i];
 		connector = fb_conn->connector;
+
+		if (connector->status == connector_status_connected)
+			num_connectors_detected++;
+
 		if (!enabled[i]) {
 			DRM_DEBUG_KMS("connector %d not enabled, skipping\n",
 				      connector->base.id);
@@ -338,6 +344,8 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 			continue;
 		}
 
+		num_connectors_enabled++;
+
 		new_crtc = intel_fb_helper_crtc(fb_helper, encoder->crtc);
 
 		/*
@@ -347,6 +355,7 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 		 */
 		for (j = 0; j < fb_helper->connector_count; j++) {
 			if (crtcs[j] == new_crtc) {
+				DRM_DEBUG_KMS("fallback: cloned configuration\n");
 				fallback = true;
 				goto out;
 			}
@@ -393,8 +402,22 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
 		fallback = false;
 	}
 
+	/*
+	 * If the BIOS didn't enable everything it could, fall back to have the
+	 * same user experiencing of lighting up as much as possible like the
+	 * fbdev helper library.
+	 */
+	if (num_connectors_enabled != num_connectors_detected &&
+	    num_connectors_enabled < INTEL_INFO(dev)->num_pipes) {
+		DRM_DEBUG_KMS("fallback: Not all outputs enabled\n");
+		DRM_DEBUG_KMS("Enabled: %i, detected: %i\n", num_connectors_enabled,
+			      num_connectors_detected);
+		fallback = true;
+	}
+
 out:
 	if (fallback) {
+		DRM_DEBUG_KMS("Not using firmware configuration\n");
 		memcpy(enabled, save_enabled, dev->mode_config.num_connector);
 		kfree(save_enabled);
 		return false;