3 files changed, 18 insertions, 6 deletions

diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index d009661781bc..ef878615c49f 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -159,6 +159,9 @@ void drm_master_put(struct drm_master **master)
 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 			struct drm_file *file_priv)
 {
+	if (file_priv->is_master)
+		return 0;
+
 	if (file_priv->minor->master && file_priv->minor->master != file_priv->master)
 		return -EINVAL;
 
@@ -169,6 +172,7 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 	    file_priv->minor->master != file_priv->master) {
 		mutex_lock(&dev->struct_mutex);
 		file_priv->minor->master = drm_master_get(file_priv->master);
+		file_priv->is_master = 1;
 		mutex_unlock(&dev->struct_mutex);
 	}
 
@@ -178,10 +182,15 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data,
 int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
 			 struct drm_file *file_priv)
 {
-	if (!file_priv->master)
+	if (!file_priv->is_master)
 		return -EINVAL;
+
+	if (!file_priv->minor->master)
+		return -EINVAL;
+
 	mutex_lock(&dev->struct_mutex);
 	drm_master_put(&file_priv->minor->master);
+	file_priv->is_master = 0;
 	mutex_unlock(&dev->struct_mutex);
 	return 0;
 }
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index bc0c6849360c..022876ae34f0 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -132,6 +132,7 @@ void drm_sysfs_destroy(void)
  */
 static void drm_sysfs_device_release(struct device *dev)
 {
+	memset(dev, 0, sizeof(struct device));
 	return;
 }
 
diff --git a/drivers/gpu/drm/via/via_dma.c b/drivers/gpu/drm/via/via_dma.c
index 7a339dba6a69..bfb92d283260 100644
--- a/drivers/gpu/drm/via/via_dma.c
+++ b/drivers/gpu/drm/via/via_dma.c
@@ -481,11 +481,13 @@ static int via_wait_idle(drm_via_private_t * dev_priv)
 {
 	int count = 10000000;
 
-	while (!(VIA_READ(VIA_REG_STATUS) & VIA_VR_QUEUE_BUSY) && count--);
+	while (!(VIA_READ(VIA_REG_STATUS) & VIA_VR_QUEUE_BUSY) && --count)
+		;
 
-	while (count-- && (VIA_READ(VIA_REG_STATUS) &
+	while (count && (VIA_READ(VIA_REG_STATUS) &
 			   (VIA_CMD_RGTR_BUSY | VIA_2D_ENG_BUSY |
-			    VIA_3D_ENG_BUSY))) ;
+			    VIA_3D_ENG_BUSY)))
+		--count;
 	return count;
 }
 
@@ -705,7 +707,7 @@ static int via_cmdbuf_size(struct drm_device *dev, void *data, struct drm_file *
 	switch (d_siz->func) {
 	case VIA_CMDBUF_SPACE:
 		while (((tmp_size = via_cmdbuf_space(dev_priv)) < d_siz->size)
-		       && count--) {
+		       && --count) {
 			if (!d_siz->wait) {
 				break;
 			}
@@ -717,7 +719,7 @@ static int via_cmdbuf_size(struct drm_device *dev, void *data, struct drm_file *
 		break;
 	case VIA_CMDBUF_LAG:
 		while (((tmp_size = via_cmdbuf_lag(dev_priv)) > d_siz->size)
-		       && count--) {
+		       && --count) {
 			if (!d_siz->wait) {
 				break;
 			}