drm: remove agp_init() bus callback

The PCI bus helper is the only user of it. Call it directly before
device-registration to get rid of the callback.

Note that all drm_agp_*() calls are locked with the drm-global-mutex so we
need to explicitly lock it during initialization. It's not really clear
why it's needed, but lets be safe.

v2: Rebase on top of the agp_init interface change.

v3: Remove the rebase-fail where I've accidentally killed the ->irq_by_busid
callback a bit too early.

Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com> (v1)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_pci.c

@@ -293,7 +293,6 @@ static struct drm_bus drm_pci_bus = {
 	.set_busid = drm_pci_set_busid,
 	.set_unique = drm_pci_set_unique,
 	.irq_by_busid = drm_pci_irq_by_busid,
-	.agp_init = drm_pci_agp_init,
 	.agp_destroy = drm_pci_agp_destroy,
 };
 
@@ -332,9 +331,13 @@ int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
 	if (drm_core_check_feature(dev, DRIVER_MODESET))
 		pci_set_drvdata(pdev, dev);
 
+	mutex_lock(&drm_global_mutex);
+	drm_pci_agp_init(dev);
+	mutex_unlock(&drm_global_mutex);
+
 	ret = drm_dev_register(dev, ent->driver_data);
 	if (ret)
-		goto err_pci;
+		goto err_agp;
 
 	DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
 		 driver->name, driver->major, driver->minor, driver->patchlevel,
@@ -347,7 +350,10 @@ int drm_get_pci_dev(struct pci_dev *pdev, const struct pci_device_id *ent,
 
 	return 0;
 
-err_pci:
+err_agp:
+	mutex_lock(&drm_global_mutex);
+	drm_pci_agp_destroy(dev);
+	mutex_unlock(&drm_global_mutex);
 	pci_disable_device(pdev);
 err_free:
 	drm_dev_free(dev);

drivers/gpu/drm/drm_stub.c

@@ -527,13 +527,10 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
 
 	mutex_lock(&drm_global_mutex);
 
-	if (dev->driver->bus->agp_init)
-		dev->driver->bus->agp_init(dev);
-
 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 		ret = drm_get_minor(dev, &dev->control, DRM_MINOR_CONTROL);
 		if (ret)
-			goto err_agp;
+			goto out_unlock;
 	}
 
 	if (drm_core_check_feature(dev, DRIVER_RENDER) && drm_rnodes) {
@@ -572,9 +569,6 @@ int drm_dev_register(struct drm_device *dev, unsigned long flags)
 	drm_put_minor(dev->render);
 err_control_node:
 	drm_put_minor(dev->control);
-err_agp:
-	if (dev->driver->bus->agp_destroy)
-		dev->driver->bus->agp_destroy(dev);
 out_unlock:
 	mutex_unlock(&drm_global_mutex);
 	return ret;

include/drm/drmP.h

@@ -767,7 +767,6 @@ struct drm_bus {
 			  struct drm_unique *unique);
 	int (*irq_by_busid)(struct drm_device *dev, struct drm_irq_busid *p);
 	/* hooks that are for PCI */
-	void (*agp_init)(struct drm_device *dev);
 	void (*agp_destroy)(struct drm_device *dev);
 
 };