drm: Remove struct drm_driver.lastclose

The lastclose callback in struct drm_driver is unused. Remove it. Also
update documentation.

v2:
- update to use drm_lastclose()
- fix typo in documentation

Signed-off-by: Thomas Zimmermann <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_file.c

···
 	if (dev->driver->load || dev->driver->unload)
 		return true;
 
-	/*
-	 * Drivers with the lastclose callback assume that it's synchronized
-	 * against concurrent opens, which again needs the BKL. The proper fix
-	 * is to use the drm_client infrastructure with proper locking for each
-	 * client.
-	 */
-	if (dev->driver->lastclose)
-		return true;
-
 	return false;
 }
 
···
 }
 EXPORT_SYMBOL(drm_open);
 
-void drm_lastclose(struct drm_device * dev)
+static void drm_lastclose(struct drm_device *dev)
 {
-	drm_dbg_core(dev, "\n");
-
-	if (dev->driver->lastclose)
-		dev->driver->lastclose(dev);
-	drm_dbg_core(dev, "driver lastclose completed\n");
-
 	drm_client_dev_restore(dev);
 
 	if (dev_is_pci(dev->dev))
···
  * @filp: file pointer.
  *
  * This function must be used by drivers as their &file_operations.release
- * method. It frees any resources associated with the open file, and calls the
- * &drm_driver.postclose driver callback. If this is the last open file for the
- * DRM device also proceeds to call the &drm_driver.lastclose driver callback.
+ * method. It frees any resources associated with the open file. If this
+ * is the last open file for the DRM device, it also restores the active
+ * in-kernel DRM client.
  *
  * RETURNS:
  *
···
  *
  * This function may be used by drivers as their &file_operations.release
  * method. It frees any resources associated with the open file prior to taking
- * the drm_global_mutex, which then calls the &drm_driver.postclose driver
- * callback. If this is the last open file for the DRM device also proceeds to
- * call the &drm_driver.lastclose driver callback.
+ * the drm_global_mutex. If this is the last open file for the DRM device, it
+ * then restores the active in-kernel DRM client.
  *
  * RETURNS:
  *

drivers/gpu/drm/drm_internal.h

···
 bool drm_dev_needs_global_mutex(struct drm_device *dev);
 struct drm_file *drm_file_alloc(struct drm_minor *minor);
 void drm_file_free(struct drm_file *file);
-void drm_lastclose(struct drm_device *dev);
 
 #ifdef CONFIG_PCI
 

include/drm/drm_drv.h

···
 	void (*postclose) (struct drm_device *, struct drm_file *);
 
 	/**
-	 * @lastclose:
-	 *
-	 * Called when the last &struct drm_file has been closed and there's
-	 * currently no userspace client for the &struct drm_device.
-	 *
-	 * Modern drivers should only use this to force-restore the fbdev
-	 * framebuffer using drm_fb_helper_restore_fbdev_mode_unlocked().
-	 * Anything else would indicate there's something seriously wrong.
-	 * Modern drivers can also use this to execute delayed power switching
-	 * state changes, e.g. in conjunction with the :ref:`vga_switcheroo`
-	 * infrastructure.
-	 *
-	 * This is called after @postclose hook has been called.
-	 *
-	 * NOTE:
-	 *
-	 * All legacy drivers use this callback to de-initialize the hardware.
-	 * This is purely because of the shadow-attach model, where the DRM
-	 * kernel driver does not really own the hardware. Instead ownershipe is
-	 * handled with the help of userspace through an inheritedly racy dance
-	 * to set/unset the VT into raw mode.
-	 *
-	 * Legacy drivers initialize the hardware in the @firstopen callback,
-	 * which isn't even called for modern drivers.
-	 */
-	void (*lastclose) (struct drm_device *);
-
-	/**
 	 * @unload:
 	 *
 	 * Reverse the effects of the driver load callback.  Ideally,