5 files changed, 48 insertions, 24 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index b0b1200ed65..2b2078695d2 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -270,7 +270,7 @@ parse_general_features(struct drm_i915_private *dev_priv,
 					general->ssc_freq ? 66 : 48;
 			else if (IS_GEN5(dev) || IS_GEN6(dev))
 				dev_priv->lvds_ssc_freq =
-					general->ssc_freq ? 100 : 120;
+					general->ssc_freq ? 120 : 100;
 			else
 				dev_priv->lvds_ssc_freq =
 					general->ssc_freq ? 100 : 96;
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index df648cb4c29..864417cffe9 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -479,6 +479,7 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 	uint16_t address = algo_data->address;
 	uint8_t msg[5];
 	uint8_t reply[2];
+	unsigned retry;
 	int msg_bytes;
 	int reply_bytes;
 	int ret;
@@ -513,14 +514,33 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 		break;
 	}
 
-	for (;;) {
-	  ret = intel_dp_aux_ch(intel_dp,
-				msg, msg_bytes,
-				reply, reply_bytes);
+	for (retry = 0; retry < 5; retry++) {
+		ret = intel_dp_aux_ch(intel_dp,
+				      msg, msg_bytes,
+				      reply, reply_bytes);
 		if (ret < 0) {
 			DRM_DEBUG_KMS("aux_ch failed %d\n", ret);
 			return ret;
 		}
+
+		switch (reply[0] & AUX_NATIVE_REPLY_MASK) {
+		case AUX_NATIVE_REPLY_ACK:
+			/* I2C-over-AUX Reply field is only valid
+			 * when paired with AUX ACK.
+			 */
+			break;
+		case AUX_NATIVE_REPLY_NACK:
+			DRM_DEBUG_KMS("aux_ch native nack\n");
+			return -EREMOTEIO;
+		case AUX_NATIVE_REPLY_DEFER:
+			udelay(100);
+			continue;
+		default:
+			DRM_ERROR("aux_ch invalid native reply 0x%02x\n",
+				  reply[0]);
+			return -EREMOTEIO;
+		}
+
 		switch (reply[0] & AUX_I2C_REPLY_MASK) {
 		case AUX_I2C_REPLY_ACK:
 			if (mode == MODE_I2C_READ) {
@@ -528,17 +548,20 @@ intel_dp_i2c_aux_ch(struct i2c_adapter *adapter, int mode,
 			}
 			return reply_bytes - 1;
 		case AUX_I2C_REPLY_NACK:
-			DRM_DEBUG_KMS("aux_ch nack\n");
+			DRM_DEBUG_KMS("aux_i2c nack\n");
 			return -EREMOTEIO;
 		case AUX_I2C_REPLY_DEFER:
-			DRM_DEBUG_KMS("aux_ch defer\n");
+			DRM_DEBUG_KMS("aux_i2c defer\n");
 			udelay(100);
 			break;
 		default:
-			DRM_ERROR("aux_ch invalid reply 0x%02x\n", reply[0]);
+			DRM_ERROR("aux_i2c invalid reply 0x%02x\n", reply[0]);
 			return -EREMOTEIO;
 		}
 	}
+
+	DRM_ERROR("too many retries, giving up\n");
+	return -EREMOTEIO;
 }
 
 static int
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 89a65be8a3f..31cd7e33e82 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -696,20 +696,17 @@ int intel_wait_ring_buffer(struct drm_device *dev,
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	u32 head;
 
-	head = intel_read_status_page(ring, 4);
-	if (head) {
-		ring->head = head & HEAD_ADDR;
-		ring->space = ring->head - (ring->tail + 8);
-		if (ring->space < 0)
-			ring->space += ring->size;
-		if (ring->space >= n)
-			return 0;
-	}
-
 	trace_i915_ring_wait_begin (dev);
 	end = jiffies + 3 * HZ;
 	do {
-		ring->head = I915_READ_HEAD(ring) & HEAD_ADDR;
+		/* If the reported head position has wrapped or hasn't advanced,
+		 * fallback to the slow and accurate path.
+		 */
+		head = intel_read_status_page(ring, 4);
+		if (head < ring->actual_head)
+			head = I915_READ_HEAD(ring);
+		ring->actual_head = head;
+		ring->head = head & HEAD_ADDR;
 		ring->space = ring->head - (ring->tail + 8);
 		if (ring->space < 0)
 			ring->space += ring->size;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 3126c268198..d2cd0f1efee 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -30,8 +30,9 @@ struct  intel_ring_buffer {
 	struct		drm_device *dev;
 	struct		drm_gem_object *gem_object;
 
-	unsigned int	head;
-	unsigned int	tail;
+	u32		actual_head;
+	u32		head;
+	u32		tail;
 	int		space;
 	struct intel_hw_status_page status_page;
 
diff --git a/drivers/gpu/drm/i915/intel_sdvo.c b/drivers/gpu/drm/i915/intel_sdvo.c
index d97e6cb52d3..27e63abf2a7 100644
--- a/drivers/gpu/drm/i915/intel_sdvo.c
+++ b/drivers/gpu/drm/i915/intel_sdvo.c
@@ -1908,9 +1908,12 @@ intel_sdvo_select_i2c_bus(struct drm_i915_private *dev_priv,
 		speed = mapping->i2c_speed;
 	}
 
-	sdvo->i2c = &dev_priv->gmbus[pin].adapter;
-	intel_gmbus_set_speed(sdvo->i2c, speed);
-	intel_gmbus_force_bit(sdvo->i2c, true);
+	if (pin < GMBUS_NUM_PORTS) {
+		sdvo->i2c = &dev_priv->gmbus[pin].adapter;
+		intel_gmbus_set_speed(sdvo->i2c, speed);
+		intel_gmbus_force_bit(sdvo->i2c, true);
+	} else
+		sdvo->i2c = &dev_priv->gmbus[GMBUS_PORT_DPB].adapter;
 }
 
 static bool