Re: [PATCH v2 8/8] fpga: region: Use standard dev_release for class driver

[Xu Yilun <yilun.xu@xxxxxxxxx>]

On Wed, Jun 09, 2021 at 03:11:35PM -0700, Russ Weight wrote:
> The FPGA region class driver data structure is being treated as a managed
> resource instead of using standard dev_release call-back to release the
> class data structure. This change populates the class.dev_release function
> and changes the fpga_region_free() function to call put_device().
> It also changes fpga_region_unregister() to call device_del() instead
> of device_unregister().
> 
> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
> ---
> v2:
>   - Moved the renaming of "dev" to "parent" to a separate patch
>   - Call fpga_region_free() in devm_fpga_region_release() instead of put_device()
> ---
>  drivers/fpga/fpga-region.c | 30 +++++++++++++++---------------
>  1 file changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
> index 563626d66e56..bdc15fab60c0 100644
> --- a/drivers/fpga/fpga-region.c
> +++ b/drivers/fpga/fpga-region.c
> @@ -204,8 +204,10 @@ struct fpga_region
>  		return NULL;
>  
>  	id = ida_simple_get(&fpga_region_ida, 0, 0, GFP_KERNEL);
> -	if (id < 0)
> -		goto err_free;
> +	if (id < 0) {
> +		kfree(region);
> +		return NULL;
> +	}
>  
>  	region->mgr = mgr;
>  	region->get_bridges = get_bridges;
> @@ -219,17 +221,12 @@ struct fpga_region
>  	region->dev.id = id;
>  
>  	ret = dev_set_name(&region->dev, "region%d", id);
> -	if (ret)
> -		goto err_remove;
> +	if (ret) {
> +		put_device(&region->dev);
> +		return NULL;
> +	}
>  
>  	return region;
> -
> -err_remove:
> -	ida_simple_remove(&fpga_region_ida, id);
> -err_free:
> -	kfree(region);
> -
> -	return NULL;
>  }
>  EXPORT_SYMBOL_GPL(fpga_region_create);
>  
> @@ -239,8 +236,7 @@ EXPORT_SYMBOL_GPL(fpga_region_create);
>   */
>  void fpga_region_free(struct fpga_region *region)
>  {
> -	ida_simple_remove(&fpga_region_ida, region->dev.id);
> -	kfree(region);
> +	put_device(&region->dev);
>  }
>  EXPORT_SYMBOL_GPL(fpga_region_free);
>  
> @@ -253,7 +249,7 @@ static void devm_fpga_region_release(struct device *dev, void *res)
>  
>  /**
>   * devm_fpga_region_create - create and initialize a managed FPGA region struct
> - * @dev: device parent
> + * @parent: device parent

This should be in Patch #5.

Others look good to me. You could append my reviewed-by after this fix.

Reviewed-by: Xu Yilun <yilun.xu@xxxxxxxxx>

>   * @mgr: manager that programs this region
>   * @get_bridges: optional function to get bridges to a list
>   *
> @@ -310,12 +306,16 @@ EXPORT_SYMBOL_GPL(fpga_region_register);
>   */
>  void fpga_region_unregister(struct fpga_region *region)
>  {
> -	device_unregister(&region->dev);
> +	device_del(&region->dev);
>  }
>  EXPORT_SYMBOL_GPL(fpga_region_unregister);
>  
>  static void fpga_region_dev_release(struct device *dev)
>  {
> +	struct fpga_region *region = to_fpga_region(dev);
> +
> +	ida_simple_remove(&fpga_region_ida, region->dev.id);
> +	kfree(region);
>  }
>  
>  /**
> -- 
> 2.25.1