3 files changed, 34 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 8ac7fbf6b2b7..08d14df3bb42 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -300,6 +300,18 @@ static int drm_open_helper(struct inode *inode, struct file *filp,
                                 goto out_free;
                         }
                 }
+                mutex_lock(&dev->struct_mutex);
+                if (dev->driver->master_set) {
+                        ret = dev->driver->master_set(dev, priv, true);
+                        if (ret) {
+                                /* drop both references if this fails */
+                                drm_master_put(&priv->minor->master);
+                                drm_master_put(&priv->master);
+                                mutex_unlock(&dev->struct_mutex);
+                                goto out_free;
+                        }
+                }
+                mutex_unlock(&dev->struct_mutex);
         } else {
                 /* get a reference to the master */
                 priv->master = drm_master_get(priv->minor->master);
@@ -533,6 +545,8 @@ int drm_release(struct inode *inode, struct file *filp)
 
                 if (file_priv->minor->master == file_priv->master) {
                         /* drop the reference held my the minor */
+                        if (dev->driver->master_drop)
+                                dev->driver->master_drop(dev, file_priv, true);
                         drm_master_put(&file_priv->minor->master);
                 }
         }
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index adb864dfef3e..2c1b52847e9e 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -174,6 +174,8 @@ void drm_master_put(struct drm_master **master)
 int drm_setmaster_ioctl(struct drm_device *dev, void *data,
                         struct drm_file *file_priv)
 {
+        int ret = 0;
+
         if (file_priv->is_master)
                 return 0;
 
@@ -188,6 +190,13 @@ int drm_setmaster_ioctl(struct drm_device *dev, void *data,
                 mutex_lock(&dev->struct_mutex);
                 file_priv->minor->master = drm_master_get(file_priv->master);
                 file_priv->is_master = 1;
+                if (dev->driver->master_set) {
+                        ret = dev->driver->master_set(dev, file_priv, false);
+                        if (unlikely(ret != 0)) {
+                                file_priv->is_master = 0;
+                                drm_master_put(&file_priv->minor->master);
+                        }
+                }
                 mutex_unlock(&dev->struct_mutex);
         }
 
@@ -204,6 +213,8 @@ int drm_dropmaster_ioctl(struct drm_device *dev, void *data,
                 return -EINVAL;
 
         mutex_lock(&dev->struct_mutex);
+        if (dev->driver->master_drop)
+                dev->driver->master_drop(dev, file_priv, false);
         drm_master_put(&file_priv->minor->master);
         file_priv->is_master = 0;
         mutex_unlock(&dev->struct_mutex);
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 1b72a526ba64..770772c014aa 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -774,6 +774,15 @@ struct drm_driver {
         /* Master routines */
         int (*master_create)(struct drm_device *dev, struct drm_master *master);
         void (*master_destroy)(struct drm_device *dev, struct drm_master *master);
+        /**
+         * master_set is called whenever the minor master is set.
+         * master_drop is called whenever the minor master is dropped.
+         */
+
+        int (*master_set)(struct drm_device *dev, struct drm_file *file_priv,
+                          bool from_open);
+        void (*master_drop)(struct drm_device *dev, struct drm_file *file_priv,
+                            bool from_release);
 
         int (*proc_init)(struct drm_minor *minor);
         void (*proc_cleanup)(struct drm_minor *minor);