1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 7d58f594cffe..df64ed1c0139 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -179,7 +179,7 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
 {
         struct drm_dp_aux_msg msg;
         unsigned int retry;
-        int err;
+        int err = 0;
 
         memset(&msg, 0, sizeof(msg));
         msg.address = offset;
@@ -187,6 +187,8 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
         msg.buffer = buffer;
         msg.size = size;
 
+        mutex_lock(&aux->hw_mutex);
+
         /*
          * The specification doesn't give any recommendation on how often to
          * retry native transactions. We used to retry 7 times like for
@@ -195,25 +197,24 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
          */
         for (retry = 0; retry < 32; retry++) {
 
-                mutex_lock(&aux->hw_mutex);
                 err = aux->transfer(aux, &msg);
-                mutex_unlock(&aux->hw_mutex);
                 if (err < 0) {
                         if (err == -EBUSY)
                                 continue;
 
-                        return err;
+                        goto unlock;
                 }
 
 
                 switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) {
                 case DP_AUX_NATIVE_REPLY_ACK:
                         if (err < size)
-                                return -EPROTO;
-                        return err;
+                                err = -EPROTO;
+                        goto unlock;
 
                 case DP_AUX_NATIVE_REPLY_NACK:
-                        return -EIO;
+                        err = -EIO;
+                        goto unlock;
 
                 case DP_AUX_NATIVE_REPLY_DEFER:
                         usleep_range(AUX_RETRY_INTERVAL, AUX_RETRY_INTERVAL + 100);
@@ -222,7 +223,11 @@ static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request,
         }
 
         DRM_DEBUG_KMS("too many retries, giving up\n");
-        return -EIO;
+        err = -EIO;
+
+unlock:
+        mutex_unlock(&aux->hw_mutex);
+        return err;
 }
 
 /**
@@ -544,9 +549,7 @@ static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
         int max_retries = max(7, drm_dp_i2c_retry_count(msg, dp_aux_i2c_speed_khz));
 
         for (retry = 0, defer_i2c = 0; retry < (max_retries + defer_i2c); retry++) {
-                mutex_lock(&aux->hw_mutex);
                 ret = aux->transfer(aux, msg);
-                mutex_unlock(&aux->hw_mutex);
                 if (ret < 0) {
                         if (ret == -EBUSY)
                                 continue;
@@ -685,6 +688,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
 
         memset(&msg, 0, sizeof(msg));
 
+        mutex_lock(&aux->hw_mutex);
+
         for (i = 0; i < num; i++) {
                 msg.address = msgs[i].addr;
                 drm_dp_i2c_msg_set_request(&msg, &msgs[i]);
@@ -739,6 +744,8 @@ static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
         msg.size = 0;
         (void)drm_dp_i2c_do_msg(aux, &msg);
 
+        mutex_unlock(&aux->hw_mutex);
+
         return err;
 }