[Intel-gfx] [PATCH] drm: Continue after failure to setup debugfs

[Chris Wilson]

If we fail to setup the debugfs we lose debugging convenience, but we
should still endeavour to enable modesetting so that we can control the
outputs and enable use of the system to debug the issue. In all
likelihood if we can not create our debugfs files then there is a larger
underlying issue that will prevent the module loading, but this should
get us further towards resilience.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: dri-devel at lists.freedesktop.org
---
 drivers/gpu/drm/drm_debugfs.c | 13 +++++++++----
 drivers/gpu/drm/drm_drv.c     | 19 ++++++++-----------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index 3bcf8e6a85b3..8f36e014fbd2 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -160,10 +160,8 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 	ret = drm_debugfs_create_files(drm_debugfs_list, DRM_DEBUGFS_ENTRIES,
 				       minor->debugfs_root, minor);
 	if (ret) {
-		debugfs_remove(minor->debugfs_root);
-		minor->debugfs_root = NULL;
 		DRM_ERROR("Failed to create core drm debugfs files\n");
-		return ret;
+		goto err_root;
 	}
 
 	if (dev->driver->debugfs_init) {
@@ -171,10 +169,17 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 		if (ret) {
 			DRM_ERROR("DRM: Driver failed to initialize "
 				  "/sys/kernel/debug/dri.\n");
-			return ret;
+			goto err_core;
 		}
 	}
 	return 0;
+
+err_core:
+	drm_debugfs_remove_files(drm_debugfs_list, DRM_DEBUGFS_ENTRIES, minor);
+err_root:
+	debugfs_remove(minor->debugfs_root);
+	minor->debugfs_root = NULL;
+	return ret;
 }
 
 
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index bff89226a344..18de82e4388a 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -307,11 +307,11 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type)
 	if (!minor)
 		return 0;
 
-	ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
-	if (ret) {
+	ret = -ENOENT;
+	if (drm_debugfs_root)
+		ret = drm_debugfs_init(minor, minor->index, drm_debugfs_root);
+	if (ret)
 		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
-		return ret;
-	}
 
 	ret = device_add(minor->kdev);
 	if (ret)
@@ -904,17 +904,13 @@ static int __init drm_core_init(void)
 	}
 
 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
-	if (!drm_debugfs_root) {
+	if (!drm_debugfs_root)
 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
-		ret = -1;
-		goto err_p3;
-	}
 
 	DRM_INFO("Initialized %s %d.%d.%d %s\n",
 		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
 	return 0;
-err_p3:
-	drm_sysfs_destroy();
+
 err_p2:
 	unregister_chrdev(DRM_MAJOR, "drm");
 
@@ -925,7 +921,8 @@ err_p1:
 
 static void __exit drm_core_exit(void)
 {
-	debugfs_remove(drm_debugfs_root);
+	if (drm_debugfs_root)
+		debugfs_remove(drm_debugfs_root);
 	drm_sysfs_destroy();
 
 	unregister_chrdev(DRM_MAJOR, "drm");
-- 
2.8.1