staging: drm/omap: add a workqueue

Add a workqueue for omapdrm driver, which is needed for at least a
couple things currently: (1) moving omap_gem_roll() to a non-atomic
context, (2) synchronizing page flips w/ DSS scanout related irq's
(in particular not unmapping previous buffer until DSS finishes
scanout).
Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/omapdrm/omap_drv.c

@@ -570,6 +570,9 @@ static int dev_load(struct drm_device *dev, unsigned long flags)
 
 	dev->dev_private = priv;
 
+	priv->wq = alloc_workqueue("omapdrm",
+			WQ_UNBOUND | WQ_NON_REENTRANT, 1);
+
 	omap_gem_init(dev);
 
 	ret = omap_modeset_init(dev);
@@ -598,6 +601,8 @@ static int dev_load(struct drm_device *dev, unsigned long flags)
 
 static int dev_unload(struct drm_device *dev)
 {
+	struct omap_drm_private *priv = dev->dev_private;
+
 	DBG("unload: dev=%p", dev);
 
 	drm_vblank_cleanup(dev);
@@ -607,6 +612,9 @@ static int dev_unload(struct drm_device *dev)
 	omap_modeset_free(dev);
 	omap_gem_deinit(dev);
 
+	flush_workqueue(priv->wq);
+	destroy_workqueue(priv->wq);
+
 	kfree(dev->dev_private);
 	dev->dev_private = NULL;
 

drivers/staging/omapdrm/omap_drv.h

@@ -51,6 +51,8 @@ struct omap_drm_private {
 
 	struct drm_fb_helper *fbdev;
 
+	struct workqueue_struct *wq;
+
 	bool has_dmm;
 };