drm: omapdrm: Simplify IRQ registration

The omapdrm can't use drm_irq_install() and drm_irq_uninstall() as it
delegates IRQ handling to the omapdss driver. However, the code still
declares IRQ-related operations used by the DRM IRQ helpers, and calls
them indirectly.

Simplify the implementation by calling the functions directly or
inlining them. The irq_enabled checks can then also be simplified as
the call stacks guarantees that omap_drm_irq_install() and
omap_drm_irq_uninstall() will never run concurrently.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/omap_drv.c

@@ -656,8 +656,7 @@ static const struct file_operations omapdriver_fops = {
 };
 
 static struct drm_driver omap_drm_driver = {
-	.driver_features = DRIVER_HAVE_IRQ | DRIVER_MODESET | DRIVER_GEM
-			 | DRIVER_PRIME,
+	.driver_features = DRIVER_MODESET | DRIVER_GEM  | DRIVER_PRIME,
 	.load = dev_load,
 	.unload = dev_unload,
 	.open = dev_open,
@@ -668,10 +667,6 @@ static struct drm_driver omap_drm_driver = {
 	.get_vblank_counter = drm_vblank_count,
 	.enable_vblank = omap_irq_enable_vblank,
 	.disable_vblank = omap_irq_disable_vblank,
-	.irq_preinstall = omap_irq_preinstall,
-	.irq_postinstall = omap_irq_postinstall,
-	.irq_uninstall = omap_irq_uninstall,
-	.irq_handler = omap_irq_handler,
 #ifdef CONFIG_DEBUG_FS
 	.debugfs_init = omap_debugfs_init,
 	.debugfs_cleanup = omap_debugfs_cleanup,

drivers/gpu/drm/omapdrm/omap_drv.h

@@ -122,15 +122,11 @@ int omap_gem_resume(struct device *dev);
 
 int omap_irq_enable_vblank(struct drm_device *dev, int crtc_id);
 void omap_irq_disable_vblank(struct drm_device *dev, int crtc_id);
-irqreturn_t omap_irq_handler(int irq, void *arg);
-void omap_irq_preinstall(struct drm_device *dev);
-int omap_irq_postinstall(struct drm_device *dev);
-void omap_irq_uninstall(struct drm_device *dev);
 void __omap_irq_register(struct drm_device *dev, struct omap_drm_irq *irq);
 void __omap_irq_unregister(struct drm_device *dev, struct omap_drm_irq *irq);
 void omap_irq_register(struct drm_device *dev, struct omap_drm_irq *irq);
 void omap_irq_unregister(struct drm_device *dev, struct omap_drm_irq *irq);
-int omap_drm_irq_uninstall(struct drm_device *dev);
+void omap_drm_irq_uninstall(struct drm_device *dev);
 int omap_drm_irq_install(struct drm_device *dev);
 
 struct drm_fb_helper *omap_fbdev_init(struct drm_device *dev);

drivers/gpu/drm/omapdrm/omap_irq.c

@@ -187,7 +187,7 @@ void omap_irq_disable_vblank(struct drm_device *dev, int crtc_id)
 	dispc_runtime_put();
 }
 
-irqreturn_t omap_irq_handler(int irq, void *arg)
+static irqreturn_t omap_irq_handler(int irq, void *arg)
 {
 	struct drm_device *dev = (struct drm_device *) arg;
 	struct omap_drm_private *priv = dev->dev_private;
@@ -222,23 +222,29 @@ irqreturn_t omap_irq_handler(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
-void omap_irq_preinstall(struct drm_device *dev)
-{
-	DBG("dev=%p", dev);
-	dispc_runtime_get();
-	dispc_clear_irqstatus(0xffffffff);
-	dispc_runtime_put();
-}
+/*
+ * We need a special version, instead of just using drm_irq_install(),
+ * because we need to register the irq via omapdss.  Once omapdss and
+ * omapdrm are merged together we can assign the dispc hwmod data to
+ * ourselves and drop these and just use drm_irq_{install,uninstall}()
+ */
 
-int omap_irq_postinstall(struct drm_device *dev)
+int omap_drm_irq_install(struct drm_device *dev)
 {
 	struct omap_drm_private *priv = dev->dev_private;
 	struct omap_drm_irq *error_handler = &priv->error_handler;
-
-	DBG("dev=%p", dev);
+	int ret;
 
 	INIT_LIST_HEAD(&priv->irq_list);
 
+	dispc_runtime_get();
+	dispc_clear_irqstatus(0xffffffff);
+	dispc_runtime_put();
+
+	ret = dispc_request_irq(omap_irq_handler, dev);
+	if (ret < 0)
+		return ret;
+
 	error_handler->irq = omap_irq_error_handler;
 	error_handler->irqmask = DISPC_IRQ_OCP_ERR;
 
@@ -249,76 +255,22 @@ int omap_irq_postinstall(struct drm_device *dev)
 
 	omap_irq_register(dev, error_handler);
 
+	dev->irq_enabled = true;
+
 	return 0;
 }
 
-void omap_irq_uninstall(struct drm_device *dev)
-{
-	DBG("dev=%p", dev);
-	// TODO prolly need to call drm_irq_uninstall() somewhere too
-}
-
-/*
- * We need a special version, instead of just using drm_irq_install(),
- * because we need to register the irq via omapdss.  Once omapdss and
- * omapdrm are merged together we can assign the dispc hwmod data to
- * ourselves and drop these and just use drm_irq_{install,uninstall}()
- */
-
-int omap_drm_irq_install(struct drm_device *dev)
-{
-	int ret;
-
-	mutex_lock(&dev->struct_mutex);
-
-	if (dev->irq_enabled) {
-		mutex_unlock(&dev->struct_mutex);
-		return -EBUSY;
-	}
-	dev->irq_enabled = true;
-	mutex_unlock(&dev->struct_mutex);
-
-	/* Before installing handler */
-	if (dev->driver->irq_preinstall)
-		dev->driver->irq_preinstall(dev);
-
-	ret = dispc_request_irq(dev->driver->irq_handler, dev);
-
-	if (ret < 0) {
-		mutex_lock(&dev->struct_mutex);
-		dev->irq_enabled = false;
-		mutex_unlock(&dev->struct_mutex);
-		return ret;
-	}
-
-	/* After installing handler */
-	if (dev->driver->irq_postinstall)
-		ret = dev->driver->irq_postinstall(dev);
-
-	if (ret < 0) {
-		mutex_lock(&dev->struct_mutex);
-		dev->irq_enabled = false;
-		mutex_unlock(&dev->struct_mutex);
-		dispc_free_irq(dev);
-	}
-
-	return ret;
-}
-
-int omap_drm_irq_uninstall(struct drm_device *dev)
+void omap_drm_irq_uninstall(struct drm_device *dev)
 {
 	unsigned long irqflags;
-	bool irq_enabled;
 	int i;
 
-	mutex_lock(&dev->struct_mutex);
-	irq_enabled = dev->irq_enabled;
-	dev->irq_enabled = false;
-	mutex_unlock(&dev->struct_mutex);
+	if (!dev->irq_enabled)
+		return;
 
-	/*
-	 * Wake up any waiters so they don't hang.
-	 */
+	dev->irq_enabled = false;
+
+	/* Wake up any waiters so they don't hang. */
 	if (dev->num_crtcs) {
 		spin_lock_irqsave(&dev->vbl_lock, irqflags);
 		for (i = 0; i < dev->num_crtcs; i++) {
@@ -330,13 +282,5 @@ int omap_drm_irq_uninstall(struct drm_device *dev)
 		spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 	}
 
-	if (!irq_enabled)
-		return -EINVAL;
-
-	if (dev->driver->irq_uninstall)
-		dev->driver->irq_uninstall(dev);
-
 	dispc_free_irq(dev);
-
-	return 0;
 }