diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c
index d6a1a6e..57f042a 100644
--- a/drivers/gpu/drm/i915/intel_crt.c
+++ b/drivers/gpu/drm/i915/intel_crt.c
@@ -32,6 +32,15 @@
 #include "intel_drv.h"
 #include "i915_drm.h"
 #include "i915_drv.h"
+static void printmodeline(struct drm_display_mode *mode)
+{
+	printk("Modeline %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x\n",
+		mode->base.id, mode->name, mode->vrefresh, mode->clock,
+		mode->hdisplay, mode->hsync_start,
+		mode->hsync_end, mode->htotal,
+		mode->vdisplay, mode->vsync_start,
+		mode->vsync_end, mode->vtotal, mode->type, mode->flags);
+}
 
 static void intel_crt_dpms(struct drm_encoder *encoder, int mode)
 {
@@ -72,19 +81,33 @@ static int intel_crt_mode_valid(struct drm_connector *connector,
 	struct drm_device *dev = connector->dev;
 
 	int max_clock = 0;
-	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+	if (mode->flags & DRM_MODE_FLAG_DBLSCAN) {
+		printk("\n DEBUG:the mode line is DBLSCAN flags is %x\n",
+			mode->flags);
+		printmodeline(mode);
 		return MODE_NO_DBLESCAN;
+	}
 
-	if (mode->clock < 25000)
+	if (mode->clock < 25000) {
+		printk("\n DEBUG:the mode line clock is less 25000,"
+			"clock is %d\n", mode->clock);
+		printmodeline(mode);
 		return MODE_CLOCK_LOW;
+	}
 
 	if (!IS_I9XX(dev))
 		max_clock = 350000;
 	else
 		max_clock = 400000;
-	if (mode->clock > max_clock)
+	if (mode->clock > max_clock) {
+		printk("\n DEBUG:the mode line clock is bigger than max value,"
+			"clock is %d\n", mode->clock);
+		printmodeline(mode);
 		return MODE_CLOCK_HIGH;
+	}
 
+	printk("DEBUG: the mode line is valid \n");
+	printmodeline(mode);
 	return MODE_OK;
 }
 
@@ -454,6 +477,15 @@ static int intel_crt_get_modes(struct drm_connector *connector)
 	intel_i2c_destroy(ddcbus);
 
 end:
+	if (ret) {
+			struct drm_display_mode *t, *cur_mode;
+			printk("\n DEBUG: print all modes from EDID START\n");
+			list_for_each_entry_safe(cur_mode, t, &connector->probed_modes, head)
+				printmodeline(cur_mode);
+			printk("\n DEBUG: print all modes from EDID END\n");
+	} else
+		printk("\n DEBUG no modes from EDID\n");
+
 	return ret;
 
 }