Commit 78f88067 authored by Aaron Thompson's avatar Aaron Thompson Committed by Danilo Krummrich
Browse files

drm/nouveau: Do not fail module init on debugfs errors 



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: 97118a18 ("drm/nouveau: create module debugfs root")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAaron Thompson <dev@aaront.org>
Acked-by: default avatarTimur Tabi <ttabi@nvidia.com>
Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250703211949.9916-1-dev@aaront.org
parent 226862f5

drivers/gpu/drm/nouveau/nouveau_debugfs.c

+1 −5
Original line number Diff line number Diff line
@@ -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

drivers/gpu/drm/nouveau/nouveau_debugfs.h

+2 −3
Original line number Diff line number Diff line
@@ -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

drivers/gpu/drm/nouveau/nouveau_drm.c

+1 −3
Original line number Diff line number Diff line
@@ -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);