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[PATCH v2 3/4] drm/mode_object: add drm_mode_object_read_refcount()

Luca Ceresoli posted 4 patches 2 weeks, 3 days ago
There is a newer version of this series
[PATCH v2 3/4] drm/mode_object: add drm_mode_object_read_refcount()
Posted by Luca Ceresoli 2 weeks, 3 days ago 
Add a wrapper to kref_read() just like the ones already in place for
kref_get() and kref_put(). This will be used for sanity checks on object
lifetime.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
 drivers/gpu/drm/drm_mode_object.c | 20 ++++++++++++++++++++
 include/drm/drm_mode_object.h     |  1 +
 2 files changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c
index df4cc0e8e263d5887a799cf1a61d998234be7158..f990cc7e9b5d3bda3453123593314fa1ea2bf923 100644
--- a/drivers/gpu/drm/drm_mode_object.c
+++ b/drivers/gpu/drm/drm_mode_object.c
@@ -217,6 +217,26 @@ void drm_mode_object_get(struct drm_mode_object *obj)
 }
 EXPORT_SYMBOL(drm_mode_object_get);
 
+/**
+ * drm_mode_object_get - read the refcount for a mode object
+ * @obj: DRM mode object
+ *
+ * This function returns the current object's refcount if it is a
+ * refcounted modeset object, or 0 on any other object.
+ */
+unsigned int drm_mode_object_read_refcount(struct drm_mode_object *obj)
+{
+	unsigned int refcount = 0;
+
+	if (obj->free_cb) {
+		refcount = kref_read(&obj->refcount);
+		DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, refcount);
+	}
+
+	return refcount;
+}
+EXPORT_SYMBOL(drm_mode_object_read_refcount);
+
 /**
  * drm_object_attach_property - attach a property to a modeset object
  * @obj: drm modeset object
diff --git a/include/drm/drm_mode_object.h b/include/drm/drm_mode_object.h
index c68edbd126d04d51221f50aa2b4166475543b59f..3d2c739e703888bf4520c61594d480f128d50e56 100644
--- a/include/drm/drm_mode_object.h
+++ b/include/drm/drm_mode_object.h
@@ -123,6 +123,7 @@ struct drm_mode_object *drm_mode_object_find(struct drm_device *dev,
 					     uint32_t id, uint32_t type);
 void drm_mode_object_get(struct drm_mode_object *obj);
 void drm_mode_object_put(struct drm_mode_object *obj);
+unsigned int drm_mode_object_read_refcount(struct drm_mode_object *obj);
 
 int drm_object_property_set_value(struct drm_mode_object *obj,
 				  struct drm_property *property,

-- 
2.34.1
Re: [PATCH v2 3/4] drm/mode_object: add drm_mode_object_read_refcount()
Posted by kernel test robot 2 weeks, 3 days ago 
Hi Luca,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 42f7652d3eb527d03665b09edac47f85fb600924]

url:    https://github.com/intel-lab-lkp/linux/commits/Luca-Ceresoli/drm-drm_mode_object-fix-typo-in-kerneldoc/20241106-185032
base:   42f7652d3eb527d03665b09edac47f85fb600924
patch link:    https://lore.kernel.org/r/20241106-drm-small-improvements-v2-3-f6e2aef86719%40bootlin.com
patch subject: [PATCH v2 3/4] drm/mode_object: add drm_mode_object_read_refcount()
config: arc-randconfig-002-20241106 (https://download.01.org/0day-ci/archive/20241107/202411070038.tZJzI7NC-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241107/202411070038.tZJzI7NC-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411070038.tZJzI7NC-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/drm_mode_object.c:228: warning: expecting prototype for drm_mode_object_get(). Prototype was for drm_mode_object_read_refcount() instead


vim +228 drivers/gpu/drm/drm_mode_object.c

   219	
   220	/**
   221	 * drm_mode_object_get - read the refcount for a mode object
   222	 * @obj: DRM mode object
   223	 *
   224	 * This function returns the current object's refcount if it is a
   225	 * refcounted modeset object, or 0 on any other object.
   226	 */
   227	unsigned int drm_mode_object_read_refcount(struct drm_mode_object *obj)
 > 228	{
   229		unsigned int refcount = 0;
   230	
   231		if (obj->free_cb) {
   232			refcount = kref_read(&obj->refcount);
   233			DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, refcount);
   234		}
   235	
   236		return refcount;
   237	}
   238	EXPORT_SYMBOL(drm_mode_object_read_refcount);
   239	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH v2 3/4] drm/mode_object: add drm_mode_object_read_refcount()
Posted by Jani Nikula 2 weeks, 3 days ago 
On Wed, 06 Nov 2024, Luca Ceresoli <luca.ceresoli@bootlin.com> wrote:
> Add a wrapper to kref_read() just like the ones already in place for
> kref_get() and kref_put(). This will be used for sanity checks on object
> lifetime.
>
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> ---
>  drivers/gpu/drm/drm_mode_object.c | 20 ++++++++++++++++++++
>  include/drm/drm_mode_object.h     |  1 +
>  2 files changed, 21 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c
> index df4cc0e8e263d5887a799cf1a61d998234be7158..f990cc7e9b5d3bda3453123593314fa1ea2bf923 100644
> --- a/drivers/gpu/drm/drm_mode_object.c
> +++ b/drivers/gpu/drm/drm_mode_object.c
> @@ -217,6 +217,26 @@ void drm_mode_object_get(struct drm_mode_object *obj)
>  }
>  EXPORT_SYMBOL(drm_mode_object_get);
>  
> +/**
> + * drm_mode_object_get - read the refcount for a mode object
> + * @obj: DRM mode object
> + *
> + * This function returns the current object's refcount if it is a
> + * refcounted modeset object, or 0 on any other object.

Returns: The current object's ...

> + */
> +unsigned int drm_mode_object_read_refcount(struct drm_mode_object *obj)
> +{
> +	unsigned int refcount = 0;
> +
> +	if (obj->free_cb) {
> +		refcount = kref_read(&obj->refcount);
> +		DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, refcount);

Please ditch the debug.

> +	}
> +
> +	return refcount;
> +}
> +EXPORT_SYMBOL(drm_mode_object_read_refcount);
> +
>  /**
>   * drm_object_attach_property - attach a property to a modeset object
>   * @obj: drm modeset object
> diff --git a/include/drm/drm_mode_object.h b/include/drm/drm_mode_object.h
> index c68edbd126d04d51221f50aa2b4166475543b59f..3d2c739e703888bf4520c61594d480f128d50e56 100644
> --- a/include/drm/drm_mode_object.h
> +++ b/include/drm/drm_mode_object.h
> @@ -123,6 +123,7 @@ struct drm_mode_object *drm_mode_object_find(struct drm_device *dev,
>  					     uint32_t id, uint32_t type);
>  void drm_mode_object_get(struct drm_mode_object *obj);
>  void drm_mode_object_put(struct drm_mode_object *obj);
> +unsigned int drm_mode_object_read_refcount(struct drm_mode_object *obj);
>  
>  int drm_object_property_set_value(struct drm_mode_object *obj,
>  				  struct drm_property *property,

-- 
Jani Nikula, Intel
Re: [PATCH v2 3/4] drm/mode_object: add drm_mode_object_read_refcount()
Posted by Luca Ceresoli 2 weeks, 3 days ago 
Hello Jani,

On Wed, 06 Nov 2024 14:03:08 +0200
Jani Nikula <jani.nikula@linux.intel.com> wrote:

> On Wed, 06 Nov 2024, Luca Ceresoli <luca.ceresoli@bootlin.com> wrote:
> > Add a wrapper to kref_read() just like the ones already in place for
> > kref_get() and kref_put(). This will be used for sanity checks on object
> > lifetime.
> >
> > Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
> > ---
> >  drivers/gpu/drm/drm_mode_object.c | 20 ++++++++++++++++++++
> >  include/drm/drm_mode_object.h     |  1 +
> >  2 files changed, 21 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c
> > index df4cc0e8e263d5887a799cf1a61d998234be7158..f990cc7e9b5d3bda3453123593314fa1ea2bf923 100644
> > --- a/drivers/gpu/drm/drm_mode_object.c
> > +++ b/drivers/gpu/drm/drm_mode_object.c
> > @@ -217,6 +217,26 @@ void drm_mode_object_get(struct drm_mode_object *obj)
> >  }
> >  EXPORT_SYMBOL(drm_mode_object_get);
> >  
> > +/**
> > + * drm_mode_object_get - read the refcount for a mode object
> > + * @obj: DRM mode object
> > + *
> > + * This function returns the current object's refcount if it is a
> > + * refcounted modeset object, or 0 on any other object.  
> 
> Returns: The current object's ...
> 
> > + */
> > +unsigned int drm_mode_object_read_refcount(struct drm_mode_object *obj)
> > +{
> > +	unsigned int refcount = 0;
> > +
> > +	if (obj->free_cb) {
> > +		refcount = kref_read(&obj->refcount);
> > +		DRM_DEBUG("OBJ ID: %d (%d)\n", obj->id, refcount);  
> 
> Please ditch the debug.

OK, will do both in v3.

Luca
-- 
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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