drm/vmwgfx: Get rid of the device-private suspended member

It was used to early block fbdev dirty processing. Replace it with an
unprotected check of the par->dirty.active field. While this might
race with the vmw_fb_off() function, we do a protected check later so
the race will at worst lead to grabbing and releasing a couple of locks.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>

drivers/gpu/drm/vmwgfx/vmwgfx_drv.c

@@ -1449,7 +1449,6 @@ static int vmw_pm_freeze(struct device *kdev)
 		DRM_ERROR("Failed to freeze modesetting.\n");
 		return ret;
 	}
-	dev_priv->suspended = true;
 	if (dev_priv->enable_fb)
 		vmw_fb_off(dev_priv);
 
@@ -1471,7 +1470,6 @@ static int vmw_pm_freeze(struct device *kdev)
 			vmw_kms_resume(dev);
 		if (dev_priv->enable_fb)
 			vmw_fb_on(dev_priv);
-		dev_priv->suspended = false;
 		vmw_fb_refresh(dev_priv);
 		return -EBUSY;
 	}
@@ -1512,7 +1510,6 @@ static int vmw_pm_restore(struct device *kdev)
 	if (dev_priv->enable_fb)
 		vmw_fb_on(dev_priv);
 
-	dev_priv->suspended = false;
 	vmw_fb_refresh(dev_priv);
 
 	return 0;

drivers/gpu/drm/vmwgfx/vmwgfx_drv.h

@@ -497,7 +497,6 @@ struct vmw_private {
 	struct vmw_master *active_master;
 	struct vmw_master fbdev_master;
 	struct notifier_block pm_nb;
-	bool suspended;
 	bool refuse_hibernation;
 	bool suspend_locked;
 

drivers/gpu/drm/vmwgfx/vmwgfx_fb.c

@@ -187,7 +187,7 @@ static void vmw_fb_dirty_flush(struct work_struct *work)
 	struct vmw_dma_buffer *vbo = par->vmw_bo;
 	void *virtual;
 
-	if (vmw_priv->suspended)
+	if (!READ_ONCE(par->dirty.active))
 		return;
 
 	mutex_lock(&par->bo_mutex);