From: Aaron Thompson dev@aaront.org

If CONFIG_DEBUG_FS is enabled, nouveau_drm_init() returns an error if it fails to create the "nouveau" directory in debugfs. One case where that will happen is when debugfs access is restricted by CONFIG_DEBUG_FS_ALLOW_NONE or by the boot parameter debugfs=off, which cause the debugfs APIs to return -EPERM.

So just ignore errors from debugfs. Note that nouveau_debugfs_root may be an error now, but that is a standard pattern for debugfs. From include/linux/debugfs.h:

"NOTE: it's expected that most callers should _ignore_ the errors returned by this function. Other debugfs functions handle the fact that the "dentry" passed to them could be an error and they don't crash in that case. Drivers should generally work fine even if debugfs fails to init anyway."

Fixes: 97118a1816d2 ("drm/nouveau: create module debugfs root") Cc: stable@vger.kernel.org Signed-off-by: Aaron Thompson dev@aaront.org --- drivers/gpu/drm/nouveau/nouveau_debugfs.c | 6 +----- drivers/gpu/drm/nouveau/nouveau_debugfs.h | 5 ++--- drivers/gpu/drm/nouveau/nouveau_drm.c | 4 +--- 3 files changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_debugfs.c b/drivers/gpu/drm/nouveau/nouveau_debugfs.c index 200e65a7cefc..c7869a639bef 100644 --- a/drivers/gpu/drm/nouveau/nouveau_debugfs.c +++ b/drivers/gpu/drm/nouveau/nouveau_debugfs.c @@ -314,14 +314,10 @@ nouveau_debugfs_fini(struct nouveau_drm *drm) drm->debugfs = NULL; }

-int +void nouveau_module_debugfs_init(void) { nouveau_debugfs_root = debugfs_create_dir("nouveau", NULL); - if (IS_ERR(nouveau_debugfs_root)) - return PTR_ERR(nouveau_debugfs_root); - - return 0; }

void diff --git a/drivers/gpu/drm/nouveau/nouveau_debugfs.h b/drivers/gpu/drm/nouveau/nouveau_debugfs.h index b7617b344ee2..d05ed0e641c4 100644 --- a/drivers/gpu/drm/nouveau/nouveau_debugfs.h +++ b/drivers/gpu/drm/nouveau/nouveau_debugfs.h @@ -24,7 +24,7 @@ extern void nouveau_debugfs_fini(struct nouveau_drm *);

extern struct dentry *nouveau_debugfs_root;

-int nouveau_module_debugfs_init(void); +void nouveau_module_debugfs_init(void); void nouveau_module_debugfs_fini(void); #else static inline void @@ -42,10 +42,9 @@ nouveau_debugfs_fini(struct nouveau_drm *drm) { }

-static inline int +static inline void nouveau_module_debugfs_init(void) { - return 0; }

static inline void diff --git a/drivers/gpu/drm/nouveau/nouveau_drm.c b/drivers/gpu/drm/nouveau/nouveau_drm.c index 0c82a63cd49d..1527b801f013 100644 --- a/drivers/gpu/drm/nouveau/nouveau_drm.c +++ b/drivers/gpu/drm/nouveau/nouveau_drm.c @@ -1461,9 +1461,7 @@ nouveau_drm_init(void) if (!nouveau_modeset) return 0;

- ret = nouveau_module_debugfs_init(); - if (ret) - return ret; + nouveau_module_debugfs_init();

#ifdef CONFIG_NOUVEAU_PLATFORM_DRIVER platform_driver_register(&nouveau_platform_driver);

base-commit: d0b3b7b22dfa1f4b515fd3a295b3fd958f9e81af