Do not check for NULL value as drm.primary->debugfs_root will either contain a valid pointer or an encoded error instead of NULL.

CC: Jani Nikula jani.nikula@linux.intel.com CC: Joonas Lahtinen joonas.lahtinen@linux.intel.com CC: Rodrigo Vivi rodrigo.vivi@intel.com CC: David Airlie airlied@linux.ie CC: Daniel Vetter daniel@ffwll.ch

Signed-off-by: Nirmoy Das nirmoy.das@amd.com --- drivers/gpu/drm/i915/gt/debugfs_gt.c | 3 --- 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/debugfs_gt.c b/drivers/gpu/drm/i915/gt/debugfs_gt.c index 591eb60785db..95ca1b3ad320 100644 --- a/drivers/gpu/drm/i915/gt/debugfs_gt.c +++ b/drivers/gpu/drm/i915/gt/debugfs_gt.c @@ -16,9 +16,6 @@ void debugfs_gt_register(struct intel_gt *gt) { struct dentry *root;

- if (!gt->i915->drm.primary->debugfs_root) - return; - root = debugfs_create_dir("gt", gt->i915->drm.primary->debugfs_root); if (IS_ERR(root)) return;

Ah there are three typos :/

s/deference/dereference for this one and for the 2nd patch as well.

Regards,

Nirmoy

On 10/13/2021 8:35 PM, Nirmoy Das wrote:

Debugfs APIs returns encoded error on failure instead of NULL and for drm primary/minor debugfs directories, we save the returned value in the dentry pointer and pass it on to drm drivers to further create debugfs files/directories. Error conditions are handled by debugfs APIs, so no need to check for NULL, as saved dentry pointers will either contain a valid pointer or an error code.

Also document this for future reference.

CC: Maarten Lankhorst maarten.lankhorst@linux.intel.com CC: Maxime Ripard mripard@kernel.org CC: Thomas Zimmermann tzimmermann@suse.de CC: David Airlie airlied@linux.ie CC: Daniel Vetter daniel@ffwll.ch

Signed-off-by: Nirmoy Das nirmoy.das@amd.com

drivers/gpu/drm/drm_debugfs.c | 9 --------- drivers/gpu/drm/drm_drv.c | 1 + include/drm/drm_file.h | 28 ++++++++++++++++++++++++---- 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c index b0a826489488..0073854a4383 100644 --- a/drivers/gpu/drm/drm_debugfs.c +++ b/drivers/gpu/drm/drm_debugfs.c @@ -272,9 +272,6 @@ static void drm_debugfs_remove_all_files(struct drm_minor *minor)

void drm_debugfs_cleanup(struct drm_minor *minor) {

• if (!minor->debugfs_root)

• return;
  

• drm_debugfs_remove_all_files(minor);

  debugfs_remove_recursive(minor->debugfs_root);

@@ -419,9 +416,6 @@ void drm_debugfs_connector_add(struct drm_connector *connector) struct drm_minor *minor = connector->dev->primary; struct dentry *root;

• if (!minor->debugfs_root)

• return;
  

• root = debugfs_create_dir(connector->name, minor->debugfs_root); connector->debugfs_entry = root;

@@ -440,9 +434,6 @@ void drm_debugfs_connector_add(struct drm_connector *connector)

void drm_debugfs_connector_remove(struct drm_connector *connector) {

• if (!connector->debugfs_entry)

• return;
  

• debugfs_remove_recursive(connector->debugfs_entry);

  connector->debugfs_entry = NULL;

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 7a5097467ba5..918f302d9c43 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -64,6 +64,7 @@ static struct idr drm_minors_idr; */ static bool drm_core_init_complete;

+/* Do not deference this pointer as it will contain ERR_PTR on error. */ static struct dentry *drm_debugfs_root;

DEFINE_STATIC_SRCU(drm_unplug_srcu); diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h index a3acb7ac3550..3a30fc4d8905 100644 --- a/include/drm/drm_file.h +++ b/include/drm/drm_file.h @@ -69,15 +69,35 @@ enum drm_minor_type { */ struct drm_minor { /* private: */

• int index; /* Minor device number */
• int type; /* Control or render */
• struct device *kdev; /* Linux device */

• /** @index: minor device number. */

• int index;

• /** @type: minor device type: primary, control, render. */

• int type;

• /** @kdev: Linux device pointer. */

• struct device *kdev;

• /** @dev: drm device pointer. */ struct drm_device *dev;

• /** @debugfs_root:

• *
  

• * Dentry for /sys/kernel/debug/dri/@index debugfs dir. Do not
  

• * deference this pointer as it will contain ERR_PTR on error.
  

• */
  

  struct dentry *debugfs_root;

• /** @debugfs_list:

• *
  

• * A list to keep track of debugfs dentries created using
  

• * drm_debugfs_create_files() by drm drivers.
  

• */
  

  struct list_head debugfs_list;

• struct mutex debugfs_lock; /* Protects debugfs_list. */

• /** @debugfs_lock: Protects debugfs_list. */

• struct mutex debugfs_lock; };

  /**

-- 2.32.0