drm/nouveau: fix multiple instances of reference count leaks

BugLink: https://bugs.launchpad.net/bugs/1892822

[ Upstream commit 659fb5f1 ]

On calling pm_runtime_get_sync() the reference count of the device
is incremented. In case of failure, decrement the
ref count before returning the error.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -805,8 +805,10 @@ nouveau_drm_open(struct drm_device *dev, struct drm_file *fpriv)
 
 	/* need to bring up power immediately if opening device */
 	ret = pm_runtime_get_sync(dev->dev);
-	if (ret < 0 && ret != -EACCES)
+	if (ret < 0 && ret != -EACCES) {
+		pm_runtime_put_autosuspend(dev->dev);
 		return ret;
+	}
 
 	get_task_comm(tmpname, current);
 	snprintf(name, sizeof(name), "%s[%d]", tmpname, pid_nr(fpriv->pid));
@@ -894,8 +896,10 @@ nouveau_drm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	long ret;
 
 	ret = pm_runtime_get_sync(dev->dev);
-	if (ret < 0 && ret != -EACCES)
+	if (ret < 0 && ret != -EACCES) {
+		pm_runtime_put_autosuspend(dev->dev);
 		return ret;
+	}
 
 	switch (_IOC_NR(cmd) - DRM_COMMAND_BASE) {
 	case DRM_NOUVEAU_NVIF:

drivers/gpu/drm/nouveau/nouveau_gem.c

@@ -42,8 +42,10 @@ nouveau_gem_object_del(struct drm_gem_object *gem)
 	int ret;
 
 	ret = pm_runtime_get_sync(dev);
-	if (WARN_ON(ret < 0 && ret != -EACCES))
+	if (WARN_ON(ret < 0 && ret != -EACCES)) {
+		pm_runtime_put_autosuspend(dev);
 		return;
+	}
 
 	if (gem->import_attach)
 		drm_prime_gem_destroy(gem, nvbo->bo.sg);