[PATCH 1/4] dri: do not check for NULL debugfs dentry

[PATCH 1/4] dri: do not check for NULL debugfs dentry

[Nirmoy Das]

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.

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 ---------
 1 file changed, 9 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;
--
2.32.0

[Intel-gfx] [PATCH 1/4] dri: do not check for NULL debugfs dentry

[Nirmoy Das]

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.

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 ---------
 1 file changed, 9 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;
--
2.32.0

[PATCH 2/4] drm/ttm: do not set NULL to debugfs dentry

[Nirmoy Das]

For debugfs directory, it is recommended to save the result
and pass over to next debugfs API for creating debugfs
files/directories. Error conditions are handled by debugfs APIs.

CC: Christian Koenig <christian.koenig@amd.com>
CC: Huang Rui <ray.huang@amd.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/ttm/ttm_device.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
index be24bb6cefd0..225ae6b0b4c2 100644
--- a/drivers/gpu/drm/ttm/ttm_device.c
+++ b/drivers/gpu/drm/ttm/ttm_device.c
@@ -77,9 +77,6 @@ static int ttm_global_init(void)
 	si_meminfo(&si);

 	ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
-	if (IS_ERR(ttm_debugfs_root)) {
-		ttm_debugfs_root = NULL;
-	}

 	/* Limit the number of pages in the pool to about 50% of the total
 	 * system memory.
@@ -108,8 +105,7 @@ static int ttm_global_init(void)
 	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
 				&glob->bo_count);
 out:
-	if (ret && ttm_debugfs_root)
-		debugfs_remove(ttm_debugfs_root);
+	debugfs_remove(ttm_debugfs_root);
 	if (ret)
 		--ttm_glob_use_count;
 	mutex_unlock(&ttm_global_mutex);
--
2.32.0

[Intel-gfx] [PATCH 2/4] drm/ttm: do not set NULL to debugfs dentry

[Nirmoy Das]

For debugfs directory, it is recommended to save the result
and pass over to next debugfs API for creating debugfs
files/directories. Error conditions are handled by debugfs APIs.

CC: Christian Koenig <christian.koenig@amd.com>
CC: Huang Rui <ray.huang@amd.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/ttm/ttm_device.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
index be24bb6cefd0..225ae6b0b4c2 100644
--- a/drivers/gpu/drm/ttm/ttm_device.c
+++ b/drivers/gpu/drm/ttm/ttm_device.c
@@ -77,9 +77,6 @@ static int ttm_global_init(void)
 	si_meminfo(&si);

 	ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
-	if (IS_ERR(ttm_debugfs_root)) {
-		ttm_debugfs_root = NULL;
-	}

 	/* Limit the number of pages in the pool to about 50% of the total
 	 * system memory.
@@ -108,8 +105,7 @@ static int ttm_global_init(void)
 	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
 				&glob->bo_count);
 out:
-	if (ret && ttm_debugfs_root)
-		debugfs_remove(ttm_debugfs_root);
+	debugfs_remove(ttm_debugfs_root);
 	if (ret)
 		--ttm_glob_use_count;
 	mutex_unlock(&ttm_global_mutex);
--
2.32.0

[PATCH 3/4] drm/i915/gt: do not check for NULL debugfs dentry

[Nirmoy Das]

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;
--
2.32.0

[Intel-gfx] [PATCH 3/4] drm/i915/gt: do not check for NULL debugfs dentry

[Nirmoy Das]

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;
--
2.32.0

[PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Nirmoy Das]

Debugfs APIs returns encoded error on failure so use
debugfs_lookup() instead of checking for NULL.

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

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
---
 drivers/gpu/vga/vga_switcheroo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 365e6ddbe90f..a331525f0b32 100644
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
 static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
 {
 	/* already initialised */
-	if (priv->debugfs_root)
+	if (debugfs_lookup("vgaswitcheroo", NULL))
 		return;

 	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
--
2.32.0

[Intel-gfx] [PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Nirmoy Das]

Debugfs APIs returns encoded error on failure so use
debugfs_lookup() instead of checking for NULL.

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

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
---
 drivers/gpu/vga/vga_switcheroo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 365e6ddbe90f..a331525f0b32 100644
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
 static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
 {
 	/* already initialised */
-	if (priv->debugfs_root)
+	if (debugfs_lookup("vgaswitcheroo", NULL))
 		return;

 	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
--
2.32.0

Re: [PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Lukas Wunner]

On Mon, Oct 11, 2021 at 09:06:07PM +0200, Nirmoy Das wrote:
> Debugfs APIs returns encoded error on failure so use
> debugfs_lookup() instead of checking for NULL.
[...]
> --- a/drivers/gpu/vga/vga_switcheroo.c
> +++ b/drivers/gpu/vga/vga_switcheroo.c
> @@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
>  static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
>  {
>  	/* already initialised */
> -	if (priv->debugfs_root)
> +	if (debugfs_lookup("vgaswitcheroo", NULL))
>  		return;
> 
>  	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);

If debugfs_create_dir() returns an error code, it does make sense to
retry the call when another vga_switcheroo client registers later.
I like that.

However I'd prefer simply changing this to explicitly check for NULL, i.e.:

-	if (priv->debugfs_root)
+	if (priv->debugfs_root == NULL)

It's just as clear as calling debugfs_lookup() and it has way less
overhead.  Granted, this isn't a hot path, but it's called on boot,
and the less code we execute, the faster the machine boots.

Thanks,

Lukas

Re: [Intel-gfx] [PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Lukas Wunner]

On Mon, Oct 11, 2021 at 09:06:07PM +0200, Nirmoy Das wrote:
> Debugfs APIs returns encoded error on failure so use
> debugfs_lookup() instead of checking for NULL.
[...]
> --- a/drivers/gpu/vga/vga_switcheroo.c
> +++ b/drivers/gpu/vga/vga_switcheroo.c
> @@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
>  static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
>  {
>  	/* already initialised */
> -	if (priv->debugfs_root)
> +	if (debugfs_lookup("vgaswitcheroo", NULL))
>  		return;
> 
>  	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);

If debugfs_create_dir() returns an error code, it does make sense to
retry the call when another vga_switcheroo client registers later.
I like that.

However I'd prefer simply changing this to explicitly check for NULL, i.e.:

-	if (priv->debugfs_root)
+	if (priv->debugfs_root == NULL)

It's just as clear as calling debugfs_lookup() and it has way less
overhead.  Granted, this isn't a hot path, but it's called on boot,
and the less code we execute, the faster the machine boots.

Thanks,

Lukas

[Intel-gfx] ✗ Fi.CI.SPARSE: warning for series starting with [1/4] dri: do not check for NULL debugfs dentry

[Patchwork]

== Series Details ==

Series: series starting with [1/4] dri: do not check for NULL debugfs dentry
URL   : https://patchwork.freedesktop.org/series/95691/
State : warning

== Summary ==

$ dim sparse --fast origin/drm-tip
Sparse version: v0.6.2
Fast mode used, each commit won't be checked separately.
-
+drivers/gpu/drm/ttm/ttm_device.c:138:5: warning: context imbalance in 'ttm_device_swapout' - wrong count at exit

[Intel-gfx] ✗ Fi.CI.BAT: failure for series starting with [1/4] dri: do not check for NULL debugfs dentry

[Patchwork]

[-- Attachment #1: Type: text/plain, Size: 18568 bytes --]

== Series Details ==

Series: series starting with [1/4] dri: do not check for NULL debugfs dentry
URL   : https://patchwork.freedesktop.org/series/95691/
State : failure

== Summary ==

CI Bug Log - changes from CI_DRM_10719 -> Patchwork_21311
====================================================

Summary
-------

  **FAILURE**

  Serious unknown changes coming with Patchwork_21311 absolutely need to be
  verified manually.
  
  If you think the reported changes have nothing to do with the changes
  introduced in Patchwork_21311, please notify your bug team to allow them
  to document this new failure mode, which will reduce false positives in CI.

  External URL: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/index.html

Possible new issues
-------------------

  Here are the unknown changes that may have been introduced in Patchwork_21311:

### IGT changes ###

#### Possible regressions ####

  * igt@core_hotunplug@unbind-rebind:
    - fi-skl-6700k2:      [PASS][1] -> [INCOMPLETE][2]
   [1]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-skl-6700k2/igt@core_hotunplug@unbind-rebind.html
   [2]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-skl-6700k2/igt@core_hotunplug@unbind-rebind.html
    - fi-rkl-guc:         [PASS][3] -> [INCOMPLETE][4]
   [3]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-rkl-guc/igt@core_hotunplug@unbind-rebind.html
   [4]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-rkl-guc/igt@core_hotunplug@unbind-rebind.html
    - fi-elk-e7500:       [PASS][5] -> [INCOMPLETE][6]
   [5]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-elk-e7500/igt@core_hotunplug@unbind-rebind.html
   [6]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-elk-e7500/igt@core_hotunplug@unbind-rebind.html
    - fi-ivb-3770:        [PASS][7] -> [INCOMPLETE][8]
   [7]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-ivb-3770/igt@core_hotunplug@unbind-rebind.html
   [8]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-ivb-3770/igt@core_hotunplug@unbind-rebind.html
    - fi-ilk-650:         [PASS][9] -> [INCOMPLETE][10]
   [9]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-ilk-650/igt@core_hotunplug@unbind-rebind.html
   [10]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-ilk-650/igt@core_hotunplug@unbind-rebind.html
    - fi-bsw-n3050:       [PASS][11] -> [INCOMPLETE][12]
   [11]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-bsw-n3050/igt@core_hotunplug@unbind-rebind.html
   [12]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bsw-n3050/igt@core_hotunplug@unbind-rebind.html
    - fi-cfl-guc:         [PASS][13] -> [INCOMPLETE][14]
   [13]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-cfl-guc/igt@core_hotunplug@unbind-rebind.html
   [14]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cfl-guc/igt@core_hotunplug@unbind-rebind.html
    - fi-skl-6600u:       [PASS][15] -> [INCOMPLETE][16]
   [15]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-skl-6600u/igt@core_hotunplug@unbind-rebind.html
   [16]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-skl-6600u/igt@core_hotunplug@unbind-rebind.html
    - fi-kbl-soraka:      [PASS][17] -> [INCOMPLETE][18]
   [17]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-kbl-soraka/igt@core_hotunplug@unbind-rebind.html
   [18]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-soraka/igt@core_hotunplug@unbind-rebind.html
    - fi-tgl-1115g4:      [PASS][19] -> [INCOMPLETE][20]
   [19]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-tgl-1115g4/igt@core_hotunplug@unbind-rebind.html
   [20]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-tgl-1115g4/igt@core_hotunplug@unbind-rebind.html
    - fi-bxt-dsi:         [PASS][21] -> [INCOMPLETE][22]
   [21]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-bxt-dsi/igt@core_hotunplug@unbind-rebind.html
   [22]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bxt-dsi/igt@core_hotunplug@unbind-rebind.html
    - fi-kbl-r:           [PASS][23] -> [INCOMPLETE][24]
   [23]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-kbl-r/igt@core_hotunplug@unbind-rebind.html
   [24]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-r/igt@core_hotunplug@unbind-rebind.html
    - fi-cfl-8700k:       [PASS][25] -> [INCOMPLETE][26]
   [25]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-cfl-8700k/igt@core_hotunplug@unbind-rebind.html
   [26]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cfl-8700k/igt@core_hotunplug@unbind-rebind.html
    - fi-rkl-11600:       [PASS][27] -> [INCOMPLETE][28]
   [27]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-rkl-11600/igt@core_hotunplug@unbind-rebind.html
   [28]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-rkl-11600/igt@core_hotunplug@unbind-rebind.html
    - fi-kbl-7500u:       [PASS][29] -> [INCOMPLETE][30]
   [29]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-kbl-7500u/igt@core_hotunplug@unbind-rebind.html
   [30]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-7500u/igt@core_hotunplug@unbind-rebind.html
    - fi-bsw-nick:        [PASS][31] -> [INCOMPLETE][32]
   [31]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-bsw-nick/igt@core_hotunplug@unbind-rebind.html
   [32]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bsw-nick/igt@core_hotunplug@unbind-rebind.html
    - fi-cfl-8109u:       [PASS][33] -> [INCOMPLETE][34]
   [33]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-cfl-8109u/igt@core_hotunplug@unbind-rebind.html
   [34]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cfl-8109u/igt@core_hotunplug@unbind-rebind.html
    - fi-kbl-guc:         [PASS][35] -> [INCOMPLETE][36]
   [35]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-kbl-guc/igt@core_hotunplug@unbind-rebind.html
   [36]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-guc/igt@core_hotunplug@unbind-rebind.html
    - fi-bwr-2160:        [PASS][37] -> [INCOMPLETE][38]
   [37]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-bwr-2160/igt@core_hotunplug@unbind-rebind.html
   [38]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bwr-2160/igt@core_hotunplug@unbind-rebind.html
    - fi-snb-2600:        [PASS][39] -> [INCOMPLETE][40]
   [39]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-snb-2600/igt@core_hotunplug@unbind-rebind.html
   [40]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-snb-2600/igt@core_hotunplug@unbind-rebind.html
    - fi-kbl-7567u:       [PASS][41] -> [DMESG-WARN][42]
   [41]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-kbl-7567u/igt@core_hotunplug@unbind-rebind.html
   [42]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-7567u/igt@core_hotunplug@unbind-rebind.html
    - fi-glk-dsi:         [PASS][43] -> [INCOMPLETE][44]
   [43]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-glk-dsi/igt@core_hotunplug@unbind-rebind.html
   [44]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-glk-dsi/igt@core_hotunplug@unbind-rebind.html
    - fi-bdw-5557u:       [PASS][45] -> [INCOMPLETE][46]
   [45]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-bdw-5557u/igt@core_hotunplug@unbind-rebind.html
   [46]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bdw-5557u/igt@core_hotunplug@unbind-rebind.html
    - fi-bsw-kefka:       [PASS][47] -> [INCOMPLETE][48]
   [47]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-bsw-kefka/igt@core_hotunplug@unbind-rebind.html
   [48]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bsw-kefka/igt@core_hotunplug@unbind-rebind.html

  * igt@i915_module_load@reload:
    - fi-cml-u2:          [PASS][49] -> [INCOMPLETE][50]
   [49]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-cml-u2/igt@i915_module_load@reload.html
   [50]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cml-u2/igt@i915_module_load@reload.html
    - fi-hsw-4770:        [PASS][51] -> [INCOMPLETE][52]
   [51]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-hsw-4770/igt@i915_module_load@reload.html
   [52]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-hsw-4770/igt@i915_module_load@reload.html
    - fi-skl-guc:         [PASS][53] -> [INCOMPLETE][54]
   [53]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-skl-guc/igt@i915_module_load@reload.html
   [54]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-skl-guc/igt@i915_module_load@reload.html
    - fi-icl-y:           [PASS][55] -> [INCOMPLETE][56]
   [55]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-icl-y/igt@i915_module_load@reload.html
   [56]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-icl-y/igt@i915_module_load@reload.html

  * igt@runner@aborted:
    - fi-bwr-2160:        NOTRUN -> [FAIL][57]
   [57]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bwr-2160/igt@runner@aborted.html
    - fi-hsw-4770:        NOTRUN -> [FAIL][58]
   [58]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-hsw-4770/igt@runner@aborted.html

  
#### Suppressed ####

  The following results come from untrusted machines, tests, or statuses.
  They do not affect the overall result.

  * igt@core_hotunplug@unbind-rebind:
    - {fi-hsw-gt1}:       [PASS][59] -> [INCOMPLETE][60]
   [59]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-hsw-gt1/igt@core_hotunplug@unbind-rebind.html
   [60]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-hsw-gt1/igt@core_hotunplug@unbind-rebind.html
    - {fi-ehl-2}:         [PASS][61] -> [INCOMPLETE][62]
   [61]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-ehl-2/igt@core_hotunplug@unbind-rebind.html
   [62]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-ehl-2/igt@core_hotunplug@unbind-rebind.html
    - {fi-tgl-dsi}:       [PASS][63] -> [INCOMPLETE][64]
   [63]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-tgl-dsi/igt@core_hotunplug@unbind-rebind.html
   [64]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-tgl-dsi/igt@core_hotunplug@unbind-rebind.html
    - {fi-jsl-1}:         [PASS][65] -> [INCOMPLETE][66]
   [65]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-jsl-1/igt@core_hotunplug@unbind-rebind.html
   [66]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-jsl-1/igt@core_hotunplug@unbind-rebind.html

  
Known issues
------------

  Here are the changes found in Patchwork_21311 that come from known issues:

### IGT changes ###

#### Issues hit ####

  * igt@core_hotunplug@unbind-rebind:
    - fi-pnv-d510:        [PASS][67] -> [INCOMPLETE][68] ([i915#299])
   [67]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-pnv-d510/igt@core_hotunplug@unbind-rebind.html
   [68]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-pnv-d510/igt@core_hotunplug@unbind-rebind.html

  * igt@kms_frontbuffer_tracking@basic:
    - fi-cml-u2:          [PASS][69] -> [DMESG-WARN][70] ([i915#4269])
   [69]: https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_10719/fi-cml-u2/igt@kms_frontbuffer_tracking@basic.html
   [70]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cml-u2/igt@kms_frontbuffer_tracking@basic.html

  * igt@runner@aborted:
    - fi-rkl-11600:       NOTRUN -> [FAIL][71] ([i915#1602])
   [71]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-rkl-11600/igt@runner@aborted.html
    - fi-ilk-650:         NOTRUN -> [FAIL][72] ([i915#2283] / [i915#2426])
   [72]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-ilk-650/igt@runner@aborted.html
    - fi-pnv-d510:        NOTRUN -> [FAIL][73] ([i915#2403])
   [73]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-pnv-d510/igt@runner@aborted.html
    - fi-bsw-kefka:       NOTRUN -> [FAIL][74] ([i915#1602] / [i915#3690])
   [74]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bsw-kefka/igt@runner@aborted.html
    - fi-cfl-8700k:       NOTRUN -> [FAIL][75] ([i915#2283] / [i915#2426] / [i915#3363])
   [75]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cfl-8700k/igt@runner@aborted.html
    - fi-skl-6600u:       NOTRUN -> [FAIL][76] ([i915#2283] / [i915#2426] / [i915#3363])
   [76]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-skl-6600u/igt@runner@aborted.html
    - fi-cfl-8109u:       NOTRUN -> [FAIL][77] ([i915#2283] / [i915#2426] / [i915#3363])
   [77]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cfl-8109u/igt@runner@aborted.html
    - fi-glk-dsi:         NOTRUN -> [FAIL][78] ([i915#2283] / [i915#2426] / [i915#3363] / [k.org#202321])
   [78]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-glk-dsi/igt@runner@aborted.html
    - fi-bsw-nick:        NOTRUN -> [FAIL][79] ([i915#1602] / [i915#3690])
   [79]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bsw-nick/igt@runner@aborted.html
    - fi-kbl-8809g:       NOTRUN -> [FAIL][80] ([i915#1569] / [i915#192] / [i915#193] / [i915#194] / [i915#3363])
   [80]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-8809g/igt@runner@aborted.html
    - fi-kbl-r:           NOTRUN -> [FAIL][81] ([i915#2283] / [i915#2426] / [i915#3363])
   [81]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-r/igt@runner@aborted.html
    - fi-bdw-5557u:       NOTRUN -> [FAIL][82] ([i915#1602] / [i915#2426])
   [82]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bdw-5557u/igt@runner@aborted.html
    - fi-kbl-soraka:      NOTRUN -> [FAIL][83] ([i915#2283] / [i915#2426] / [i915#3363])
   [83]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-soraka/igt@runner@aborted.html
    - fi-kbl-7500u:       NOTRUN -> [FAIL][84] ([i915#2283] / [i915#2426] / [i915#3363])
   [84]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-7500u/igt@runner@aborted.html
    - fi-kbl-guc:         NOTRUN -> [FAIL][85] ([i915#2283] / [i915#2426] / [i915#3363])
   [85]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-guc/igt@runner@aborted.html
    - fi-snb-2600:        NOTRUN -> [FAIL][86] ([i915#2426])
   [86]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-snb-2600/igt@runner@aborted.html
    - fi-cml-u2:          NOTRUN -> [FAIL][87] ([i915#2082] / [i915#2426] / [i915#3363])
   [87]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cml-u2/igt@runner@aborted.html
    - fi-rkl-guc:         NOTRUN -> [FAIL][88] ([i915#1602] / [i915#2426])
   [88]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-rkl-guc/igt@runner@aborted.html
    - fi-ivb-3770:        NOTRUN -> [FAIL][89] ([i915#2426])
   [89]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-ivb-3770/igt@runner@aborted.html
    - fi-bxt-dsi:         NOTRUN -> [FAIL][90] ([i915#2283] / [i915#2426] / [i915#3363])
   [90]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bxt-dsi/igt@runner@aborted.html
    - fi-tgl-1115g4:      NOTRUN -> [FAIL][91] ([i915#1602] / [i915#3690])
   [91]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-tgl-1115g4/igt@runner@aborted.html
    - fi-elk-e7500:       NOTRUN -> [FAIL][92] ([i915#2426])
   [92]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-elk-e7500/igt@runner@aborted.html
    - fi-cfl-guc:         NOTRUN -> [FAIL][93] ([i915#2283] / [i915#2426] / [i915#3363])
   [93]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-cfl-guc/igt@runner@aborted.html
    - fi-icl-y:           NOTRUN -> [FAIL][94] ([i915#3690])
   [94]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-icl-y/igt@runner@aborted.html
    - fi-kbl-7567u:       NOTRUN -> [FAIL][95] ([i915#2283] / [i915#3363])
   [95]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-kbl-7567u/igt@runner@aborted.html
    - fi-skl-guc:         NOTRUN -> [FAIL][96] ([i915#2426] / [i915#3363])
   [96]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-skl-guc/igt@runner@aborted.html
    - fi-skl-6700k2:      NOTRUN -> [FAIL][97] ([i915#2283] / [i915#2426] / [i915#3363])
   [97]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-skl-6700k2/igt@runner@aborted.html
    - fi-bsw-n3050:       NOTRUN -> [FAIL][98] ([i915#1602] / [i915#3690])
   [98]: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/fi-bsw-n3050/igt@runner@aborted.html

  
  {name}: This element is suppressed. This means it is ignored when computing
          the status of the difference (SUCCESS, WARNING, or FAILURE).

  [i915#1569]: https://gitlab.freedesktop.org/drm/intel/issues/1569
  [i915#1602]: https://gitlab.freedesktop.org/drm/intel/issues/1602
  [i915#192]: https://gitlab.freedesktop.org/drm/intel/issues/192
  [i915#193]: https://gitlab.freedesktop.org/drm/intel/issues/193
  [i915#194]: https://gitlab.freedesktop.org/drm/intel/issues/194
  [i915#2082]: https://gitlab.freedesktop.org/drm/intel/issues/2082
  [i915#2283]: https://gitlab.freedesktop.org/drm/intel/issues/2283
  [i915#2403]: https://gitlab.freedesktop.org/drm/intel/issues/2403
  [i915#2426]: https://gitlab.freedesktop.org/drm/intel/issues/2426
  [i915#2932]: https://gitlab.freedesktop.org/drm/intel/issues/2932
  [i915#299]: https://gitlab.freedesktop.org/drm/intel/issues/299
  [i915#3363]: https://gitlab.freedesktop.org/drm/intel/issues/3363
  [i915#3690]: https://gitlab.freedesktop.org/drm/intel/issues/3690
  [i915#4269]: https://gitlab.freedesktop.org/drm/intel/issues/4269
  [k.org#202321]: https://bugzilla.kernel.org/show_bug.cgi?id=202321


Participating hosts (38 -> 37)
------------------------------

  Missing    (1): fi-bsw-cyan 


Build changes
-------------

  * Linux: CI_DRM_10719 -> Patchwork_21311

  CI-20190529: 20190529
  CI_DRM_10719: b138938ad4071c045a865977718019951186e322 @ git://anongit.freedesktop.org/gfx-ci/linux
  IGT_6242: 721fd85ee95225ed5df322f7182bdfa9b86a3e68 @ https://gitlab.freedesktop.org/drm/igt-gpu-tools.git
  Patchwork_21311: 5613e87998ba5250a0bb5bbe57e2718439850ee8 @ git://anongit.freedesktop.org/gfx-ci/linux


== Linux commits ==

5613e87998ba vgaswitcheroo: do not check for NULL debugfs dentry
4475fbd733da drm/i915/gt: do not check for NULL debugfs dentry
9aca8c9580d8 drm/ttm: do not set NULL to debugfs dentry
a6b52454e95d dri: do not check for NULL debugfs dentry

== Logs ==

For more details see: https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_21311/index.html

[-- Attachment #2: Type: text/html, Size: 23633 bytes --]

Re: [PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Lukas Wunner]

On Mon, Oct 11, 2021 at 10:24:29PM +0200, Lukas Wunner wrote:
> On Mon, Oct 11, 2021 at 09:06:07PM +0200, Nirmoy Das wrote:
> > Debugfs APIs returns encoded error on failure so use
> > debugfs_lookup() instead of checking for NULL.
> [...]
> > --- a/drivers/gpu/vga/vga_switcheroo.c
> > +++ b/drivers/gpu/vga/vga_switcheroo.c
> > @@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
> >  static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
> >  {
> >  	/* already initialised */
> > -	if (priv->debugfs_root)
> > +	if (debugfs_lookup("vgaswitcheroo", NULL))
> >  		return;
> > 
> >  	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
> 
> If debugfs_create_dir() returns an error code, it does make sense to
> retry the call when another vga_switcheroo client registers later.
> I like that.
> 
> However I'd prefer simply changing this to explicitly check for NULL, i.e.:
> 
> -	if (priv->debugfs_root)
> +	if (priv->debugfs_root == NULL)

Apologies, I meant:

-	if (priv->debugfs_root)
+	if (priv->debugfs_root && !IS_ERR(priv->debugfs_root))

Thanks,

Lukas

> It's just as clear as calling debugfs_lookup() and it has way less
> overhead.  Granted, this isn't a hot path, but it's called on boot,
> and the less code we execute, the faster the machine boots.

Re: [Intel-gfx] [PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Lukas Wunner]

On Mon, Oct 11, 2021 at 10:24:29PM +0200, Lukas Wunner wrote:
> On Mon, Oct 11, 2021 at 09:06:07PM +0200, Nirmoy Das wrote:
> > Debugfs APIs returns encoded error on failure so use
> > debugfs_lookup() instead of checking for NULL.
> [...]
> > --- a/drivers/gpu/vga/vga_switcheroo.c
> > +++ b/drivers/gpu/vga/vga_switcheroo.c
> > @@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
> >  static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
> >  {
> >  	/* already initialised */
> > -	if (priv->debugfs_root)
> > +	if (debugfs_lookup("vgaswitcheroo", NULL))
> >  		return;
> > 
> >  	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
> 
> If debugfs_create_dir() returns an error code, it does make sense to
> retry the call when another vga_switcheroo client registers later.
> I like that.
> 
> However I'd prefer simply changing this to explicitly check for NULL, i.e.:
> 
> -	if (priv->debugfs_root)
> +	if (priv->debugfs_root == NULL)

Apologies, I meant:

-	if (priv->debugfs_root)
+	if (priv->debugfs_root && !IS_ERR(priv->debugfs_root))

Thanks,

Lukas

> It's just as clear as calling debugfs_lookup() and it has way less
> overhead.  Granted, this isn't a hot path, but it's called on boot,
> and the less code we execute, the faster the machine boots.

Re: [PATCH 2/4] drm/ttm: do not set NULL to debugfs dentry

[Christian König]

Am 11.10.21 um 21:06 schrieb Nirmoy Das:
> For debugfs directory, it is recommended to save the result
> and pass over to next debugfs API for creating debugfs
> files/directories. Error conditions are handled by debugfs APIs.
>
> CC: Christian Koenig <christian.koenig@amd.com>
> CC: Huang Rui <ray.huang@amd.com>
> CC: David Airlie <airlied@linux.ie>
> CC: Daniel Vetter <daniel@ffwll.ch>
>
> Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>

Please also add a comment to ttm_debugfs_root that this can also be an 
ERR_PTR and should not be dereferenced.

Apart from that looks good to me.

Christian.

> ---
>   drivers/gpu/drm/ttm/ttm_device.c | 6 +-----
>   1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
> index be24bb6cefd0..225ae6b0b4c2 100644
> --- a/drivers/gpu/drm/ttm/ttm_device.c
> +++ b/drivers/gpu/drm/ttm/ttm_device.c
> @@ -77,9 +77,6 @@ static int ttm_global_init(void)
>   	si_meminfo(&si);
>
>   	ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
> -	if (IS_ERR(ttm_debugfs_root)) {
> -		ttm_debugfs_root = NULL;
> -	}
>
>   	/* Limit the number of pages in the pool to about 50% of the total
>   	 * system memory.
> @@ -108,8 +105,7 @@ static int ttm_global_init(void)
>   	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
>   				&glob->bo_count);
>   out:
> -	if (ret && ttm_debugfs_root)
> -		debugfs_remove(ttm_debugfs_root);
> +	debugfs_remove(ttm_debugfs_root);
>   	if (ret)
>   		--ttm_glob_use_count;
>   	mutex_unlock(&ttm_global_mutex);
> --
> 2.32.0
>

Re: [Intel-gfx] [PATCH 2/4] drm/ttm: do not set NULL to debugfs dentry

[Christian König]

Am 11.10.21 um 21:06 schrieb Nirmoy Das:
> For debugfs directory, it is recommended to save the result
> and pass over to next debugfs API for creating debugfs
> files/directories. Error conditions are handled by debugfs APIs.
>
> CC: Christian Koenig <christian.koenig@amd.com>
> CC: Huang Rui <ray.huang@amd.com>
> CC: David Airlie <airlied@linux.ie>
> CC: Daniel Vetter <daniel@ffwll.ch>
>
> Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>

Please also add a comment to ttm_debugfs_root that this can also be an 
ERR_PTR and should not be dereferenced.

Apart from that looks good to me.

Christian.

> ---
>   drivers/gpu/drm/ttm/ttm_device.c | 6 +-----
>   1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
> index be24bb6cefd0..225ae6b0b4c2 100644
> --- a/drivers/gpu/drm/ttm/ttm_device.c
> +++ b/drivers/gpu/drm/ttm/ttm_device.c
> @@ -77,9 +77,6 @@ static int ttm_global_init(void)
>   	si_meminfo(&si);
>
>   	ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
> -	if (IS_ERR(ttm_debugfs_root)) {
> -		ttm_debugfs_root = NULL;
> -	}
>
>   	/* Limit the number of pages in the pool to about 50% of the total
>   	 * system memory.
> @@ -108,8 +105,7 @@ static int ttm_global_init(void)
>   	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
>   				&glob->bo_count);
>   out:
> -	if (ret && ttm_debugfs_root)
> -		debugfs_remove(ttm_debugfs_root);
> +	debugfs_remove(ttm_debugfs_root);
>   	if (ret)
>   		--ttm_glob_use_count;
>   	mutex_unlock(&ttm_global_mutex);
> --
> 2.32.0
>

Re: [PATCH 2/4] drm/ttm: do not set NULL to debugfs dentry

[Das, Nirmoy]

On 10/12/2021 9:09 AM, Christian König wrote:
> Am 11.10.21 um 21:06 schrieb Nirmoy Das:
>> For debugfs directory, it is recommended to save the result
>> and pass over to next debugfs API for creating debugfs
>> files/directories. Error conditions are handled by debugfs APIs.
>>
>> CC: Christian Koenig <christian.koenig@amd.com>
>> CC: Huang Rui <ray.huang@amd.com>
>> CC: David Airlie <airlied@linux.ie>
>> CC: Daniel Vetter <daniel@ffwll.ch>
>>
>> Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
>
> Please also add a comment to ttm_debugfs_root that this can also be an 
> ERR_PTR and should not be dereferenced.


Thanks, I will resend with a comment to ttm_debugfs_root.


Nirmoy

>
> Apart from that looks good to me.
>
> Christian.
>
>> ---
>>   drivers/gpu/drm/ttm/ttm_device.c | 6 +-----
>>   1 file changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_device.c 
>> b/drivers/gpu/drm/ttm/ttm_device.c
>> index be24bb6cefd0..225ae6b0b4c2 100644
>> --- a/drivers/gpu/drm/ttm/ttm_device.c
>> +++ b/drivers/gpu/drm/ttm/ttm_device.c
>> @@ -77,9 +77,6 @@ static int ttm_global_init(void)
>>       si_meminfo(&si);
>>
>>       ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
>> -    if (IS_ERR(ttm_debugfs_root)) {
>> -        ttm_debugfs_root = NULL;
>> -    }
>>
>>       /* Limit the number of pages in the pool to about 50% of the total
>>        * system memory.
>> @@ -108,8 +105,7 @@ static int ttm_global_init(void)
>>       debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
>>                   &glob->bo_count);
>>   out:
>> -    if (ret && ttm_debugfs_root)
>> -        debugfs_remove(ttm_debugfs_root);
>> +    debugfs_remove(ttm_debugfs_root);
>>       if (ret)
>>           --ttm_glob_use_count;
>>       mutex_unlock(&ttm_global_mutex);
>> -- 
>> 2.32.0
>>
>

Re: [Intel-gfx] [PATCH 2/4] drm/ttm: do not set NULL to debugfs dentry

[Das, Nirmoy]

On 10/12/2021 9:09 AM, Christian König wrote:
> Am 11.10.21 um 21:06 schrieb Nirmoy Das:
>> For debugfs directory, it is recommended to save the result
>> and pass over to next debugfs API for creating debugfs
>> files/directories. Error conditions are handled by debugfs APIs.
>>
>> CC: Christian Koenig <christian.koenig@amd.com>
>> CC: Huang Rui <ray.huang@amd.com>
>> CC: David Airlie <airlied@linux.ie>
>> CC: Daniel Vetter <daniel@ffwll.ch>
>>
>> Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
>
> Please also add a comment to ttm_debugfs_root that this can also be an 
> ERR_PTR and should not be dereferenced.


Thanks, I will resend with a comment to ttm_debugfs_root.


Nirmoy

>
> Apart from that looks good to me.
>
> Christian.
>
>> ---
>>   drivers/gpu/drm/ttm/ttm_device.c | 6 +-----
>>   1 file changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_device.c 
>> b/drivers/gpu/drm/ttm/ttm_device.c
>> index be24bb6cefd0..225ae6b0b4c2 100644
>> --- a/drivers/gpu/drm/ttm/ttm_device.c
>> +++ b/drivers/gpu/drm/ttm/ttm_device.c
>> @@ -77,9 +77,6 @@ static int ttm_global_init(void)
>>       si_meminfo(&si);
>>
>>       ttm_debugfs_root = debugfs_create_dir("ttm", NULL);
>> -    if (IS_ERR(ttm_debugfs_root)) {
>> -        ttm_debugfs_root = NULL;
>> -    }
>>
>>       /* Limit the number of pages in the pool to about 50% of the total
>>        * system memory.
>> @@ -108,8 +105,7 @@ static int ttm_global_init(void)
>>       debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
>>                   &glob->bo_count);
>>   out:
>> -    if (ret && ttm_debugfs_root)
>> -        debugfs_remove(ttm_debugfs_root);
>> +    debugfs_remove(ttm_debugfs_root);
>>       if (ret)
>>           --ttm_glob_use_count;
>>       mutex_unlock(&ttm_global_mutex);
>> -- 
>> 2.32.0
>>
>

Re: [Intel-gfx] [PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Das, Nirmoy]

On 10/12/2021 8:48 AM, Lukas Wunner wrote:
> On Mon, Oct 11, 2021 at 10:24:29PM +0200, Lukas Wunner wrote:
>> On Mon, Oct 11, 2021 at 09:06:07PM +0200, Nirmoy Das wrote:
>>> Debugfs APIs returns encoded error on failure so use
>>> debugfs_lookup() instead of checking for NULL.
>> [...]
>>> --- a/drivers/gpu/vga/vga_switcheroo.c
>>> +++ b/drivers/gpu/vga/vga_switcheroo.c
>>> @@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
>>>   static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
>>>   {
>>>   	/* already initialised */
>>> -	if (priv->debugfs_root)
>>> +	if (debugfs_lookup("vgaswitcheroo", NULL))
>>>   		return;
>>>
>>>   	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
>> If debugfs_create_dir() returns an error code, it does make sense to
>> retry the call when another vga_switcheroo client registers later.
>> I like that.
>>
>> However I'd prefer simply changing this to explicitly check for NULL, i.e.:
>>
>> -	if (priv->debugfs_root)
>> +	if (priv->debugfs_root == NULL)
> Apologies, I meant:
>
> -	if (priv->debugfs_root)
> +	if (priv->debugfs_root && !IS_ERR(priv->debugfs_root))


Thanks for the suggestion, Lukas. I will update that and resend.


Nirmoy


> Thanks,
>
> Lukas
>
>> It's just as clear as calling debugfs_lookup() and it has way less
>> overhead.  Granted, this isn't a hot path, but it's called on boot,
>> and the less code we execute, the faster the machine boots.

Re: [PATCH 4/4] vgaswitcheroo: do not check for NULL debugfs dentry

[Das, Nirmoy]

On 10/12/2021 8:48 AM, Lukas Wunner wrote:
> On Mon, Oct 11, 2021 at 10:24:29PM +0200, Lukas Wunner wrote:
>> On Mon, Oct 11, 2021 at 09:06:07PM +0200, Nirmoy Das wrote:
>>> Debugfs APIs returns encoded error on failure so use
>>> debugfs_lookup() instead of checking for NULL.
>> [...]
>>> --- a/drivers/gpu/vga/vga_switcheroo.c
>>> +++ b/drivers/gpu/vga/vga_switcheroo.c
>>> @@ -914,7 +914,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv)
>>>   static void vga_switcheroo_debugfs_init(struct vgasr_priv *priv)
>>>   {
>>>   	/* already initialised */
>>> -	if (priv->debugfs_root)
>>> +	if (debugfs_lookup("vgaswitcheroo", NULL))
>>>   		return;
>>>
>>>   	priv->debugfs_root = debugfs_create_dir("vgaswitcheroo", NULL);
>> If debugfs_create_dir() returns an error code, it does make sense to
>> retry the call when another vga_switcheroo client registers later.
>> I like that.
>>
>> However I'd prefer simply changing this to explicitly check for NULL, i.e.:
>>
>> -	if (priv->debugfs_root)
>> +	if (priv->debugfs_root == NULL)
> Apologies, I meant:
>
> -	if (priv->debugfs_root)
> +	if (priv->debugfs_root && !IS_ERR(priv->debugfs_root))


Thanks for the suggestion, Lukas. I will update that and resend.


Nirmoy


> Thanks,
>
> Lukas
>
>> It's just as clear as calling debugfs_lookup() and it has way less
>> overhead.  Granted, this isn't a hot path, but it's called on boot,
>> and the less code we execute, the faster the machine boots.