diff --git a/drivers/gpu/drm/radeon/radeon_cp.c b/drivers/gpu/drm/radeon/radeon_cp.c
index 248ab4a..c698ecd 100644
--- a/drivers/gpu/drm/radeon/radeon_cp.c
+++ b/drivers/gpu/drm/radeon/radeon_cp.c
@@ -252,9 +252,10 @@ static int radeon_do_wait_for_idle(drm_radeon_private_t * dev_priv)
 		}
 		DRM_UDELAY(1);
 	}
-	DRM_DEBUG("wait idle failed status : 0x%08X 0x%08X\n",
+	DRM_DEBUG("wait idle failed status : 0x%08X 0x%08X 0x%08X\n",
 		 RADEON_READ(RADEON_RBBM_STATUS),
-		 RADEON_READ(R300_VAP_CNTL_STATUS));
+		 RADEON_READ(R300_VAP_CNTL_STATUS),
+		 RADEON_READ(0x7C0));
 
 #if RADEON_FIFO_DEBUG
 	DRM_ERROR("failed!\n");
@@ -646,8 +647,26 @@ static void radeon_cp_init_ring_buffer(struct drm_device * dev,
 	RADEON_WRITE(RADEON_SCRATCH_UMSK, 0x7);
 
 	/* Turn on bus mastering */
+	DRM_INFO("initial BUS_CNTL  : 0x%08X\n", RADEON_READ(RADEON_BUS_CNTL));
+	DRM_INFO("initial BUS_CNTL1 : 0x%08X\n", RADEON_READ(0x34));
 	tmp = RADEON_READ(RADEON_BUS_CNTL) & ~RADEON_BUS_MASTER_DIS;
+	/* enable :
+	 * BUS_MSTR_DISCONNECT_EN (1 << 28)
+	 * BUS_RD_DISCARD_EN (1 << 24)
+	 * BUS_MSTR_RD_LINE (1 << 21)
+	 * BUS_MSTR_RD_MULT (1 << 20)
+	 * BUS_PCI_WRT_RETRY_EN (1 << 15)
+	 * BUS_PCI_READ_RETRY_EN (1 << 13)
+	 * BUS_NON_PM4_READ_COMBINE_EN (1 << 9)
+	 * BUS_WRT_COMBINE_EN (1 << 5)
+	 */
+	tmp |= (1 << 28) | (1 << 24) | (1 << 21) | (1 << 20) | (1 << 15);
+	tmp |= (1 << 13) | (1 << 9) | (1 << 5);
 	RADEON_WRITE(RADEON_BUS_CNTL, tmp);
+	tmp = RADEON_READ(0x34);
+	RADEON_WRITE(0x34, tmp);
+	DRM_INFO("set BUS_CNTL  : 0x%08X\n", RADEON_READ(RADEON_BUS_CNTL));
+	DRM_INFO("set BUS_CNTL1 : 0x%08X\n", RADEON_READ(0x34));
 
 	dev_priv->sarea_priv->last_frame = dev_priv->scratch[0] = 0;
 	RADEON_WRITE(RADEON_LAST_FRAME_REG, dev_priv->sarea_priv->last_frame);
@@ -1519,7 +1538,7 @@ struct drm_buf *radeon_freelist_get(struct drm_device * dev)
 
 	for (t = 0; t < dev_priv->usec_timeout; t++) {
 		u32 done_age = GET_SCRATCH(1);
-		DRM_DEBUG("done_age = %d\n", done_age);
+//		DRM_DEBUG("done_age = %d\n", done_age);
 		for (i = start; i < dma->buf_count; i++) {
 			buf = dma->buflist[i];
 			buf_priv = buf->dev_private;
diff --git a/drivers/gpu/drm/radeon/radeon_irq.c b/drivers/gpu/drm/radeon/radeon_irq.c
index ee40d19..553b4b2 100644
--- a/drivers/gpu/drm/radeon/radeon_irq.c
+++ b/drivers/gpu/drm/radeon/radeon_irq.c
@@ -38,9 +38,12 @@
 static __inline__ u32 radeon_acknowledge_irqs(drm_radeon_private_t * dev_priv,
 					      u32 mask)
 {
-	u32 irqs = RADEON_READ(RADEON_GEN_INT_STATUS) & mask;
+	u32 irqs = RADEON_READ(RADEON_GEN_INT_STATUS);
+	if (irqs & (~mask)) {
+		DRM_INFO("irq not acking : 0x%08X\n", irqs & (~mask));
+	}
 	if (irqs)
-		RADEON_WRITE(RADEON_GEN_INT_STATUS, irqs);
+		RADEON_WRITE(RADEON_GEN_INT_STATUS, irqs & mask);
 	return irqs;
 }