[PATCH v2 3/9] drm: Simplify drmm_alloc_ordered_workqueue return

[Matthew Brost]

On Wed, Jul 02, 2025 at 04:42:16PM -0700, Matthew Brost wrote:
> Rather than returning ERR_PTR or NULL on failure, replace the NULL
> return with ERR_PTR(-ENOMEM). This simplifies error handling at the
> caller. While here, add kernel documentation for
> drmm_alloc_ordered_workqueue.
> 
> Cc: Louis Chauvet <louis.chauvet at bootlin.com>
> Signed-off-by: Matthew Brost <matthew.brost at intel.com>

This one is already merged through drm-xe-misc.

Matt

> ---
>  drivers/gpu/drm/vkms/vkms_crtc.c |  2 --
>  include/drm/drm_managed.h        | 15 +++++++++++++--
>  2 files changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c b/drivers/gpu/drm/vkms/vkms_crtc.c
> index 8c9898b9055d..e60573e0f3e9 100644
> --- a/drivers/gpu/drm/vkms/vkms_crtc.c
> +++ b/drivers/gpu/drm/vkms/vkms_crtc.c
> @@ -302,8 +302,6 @@ struct vkms_output *vkms_crtc_init(struct drm_device *dev, struct drm_plane *pri
>  	vkms_out->composer_workq = drmm_alloc_ordered_workqueue(dev, "vkms_composer", 0);
>  	if (IS_ERR(vkms_out->composer_workq))
>  		return ERR_CAST(vkms_out->composer_workq);
> -	if (!vkms_out->composer_workq)
> -		return ERR_PTR(-ENOMEM);
>  
>  	return vkms_out;
>  }
> diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h
> index 53017cc609ac..72bfac002c06 100644
> --- a/include/drm/drm_managed.h
> +++ b/include/drm/drm_managed.h
> @@ -129,14 +129,25 @@ void __drmm_mutex_release(struct drm_device *dev, void *res);
>  
>  void __drmm_workqueue_release(struct drm_device *device, void *wq);
>  
> +/**
> + * drmm_alloc_ordered_workqueue - &drm_device managed alloc_ordered_workqueue()
> + * @dev: DRM device
> + * @fmt: printf format for the name of the workqueue
> + * @flags: WQ_* flags (only WQ_FREEZABLE and WQ_MEM_RECLAIM are meaningful)
> + * @args: args for @fmt
> + *
> + * This is a &drm_device-managed version of alloc_ordered_workqueue(). The
> + * allocated workqueue is automatically destroyed on the final drm_dev_put().
> + *
> + * Returns: workqueue on success, negative ERR_PTR otherwise.
> + */
>  #define drmm_alloc_ordered_workqueue(dev, fmt, flags, args...)					\
>  	({											\
>  		struct workqueue_struct *wq = alloc_ordered_workqueue(fmt, flags, ##args);	\
>  		wq ? ({										\
>  			int ret = drmm_add_action_or_reset(dev, __drmm_workqueue_release, wq);	\
>  			ret ? ERR_PTR(ret) : wq;						\
> -		}) :										\
> -			wq;									\
> +		}) : ERR_PTR(-ENOMEM);								\
>  	})
>  
>  #endif
> -- 
> 2.34.1
>