Re: [PATCH 6/9] drm/{i915,xe}/fbdev: add intel_fbdev_fb_bo_destroy()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Sep 03, 2025 at 11:32:03PM +0300, Jani Nikula wrote:
> xe does xe_bo_unpin_map_no_vm() on the failure path. Add a common helper
> to enable further refactoring.
> 
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_fbdev_fb.c | 5 +++++
>  drivers/gpu/drm/i915/display/intel_fbdev_fb.h | 1 +
>  drivers/gpu/drm/xe/display/intel_fbdev_fb.c   | 7 ++++++-
>  3 files changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
> index 3837973b0d25..6b70823ce5ef 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev_fb.c
> @@ -51,6 +51,11 @@ struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size
>  	return &obj->base;
>  }
>  
> +void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj)
> +{
> +	/* nop? */

gem_object_put() is what destroys the bo on i915, so I think you're
introducing a leak in the next patch with this nop implementation.

xe seems to be riddled with footguns here since it conflates
creation+pinning+whatever in the same thing (and I guess it
doesn't know how to clean all that up when the last reference
to the object disappears?) and you have to use that horribly
misnamed function instead...

> +}
> +
>  struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_device *drm,
>  					       struct drm_mode_fb_cmd2 *mode_cmd)
>  {
> diff --git a/drivers/gpu/drm/i915/display/intel_fbdev_fb.h b/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
> index b10c4635bf46..6d6f316834df 100644
> --- a/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
> +++ b/drivers/gpu/drm/i915/display/intel_fbdev_fb.h
> @@ -17,6 +17,7 @@ struct intel_display;
>  
>  u32 intel_fbdev_fb_pitch_align(u32 stride);
>  struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size);
> +void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj);
>  struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_device *drm,
>  					       struct drm_mode_fb_cmd2 *mode_cmd);
>  int intel_fbdev_fb_fill_info(struct intel_display *display, struct fb_info *info,
> diff --git a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
> index 9a5d14d5781a..9a5cf50ea7de 100644
> --- a/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
> +++ b/drivers/gpu/drm/xe/display/intel_fbdev_fb.c
> @@ -54,6 +54,11 @@ struct drm_gem_object *intel_fbdev_fb_bo_create(struct drm_device *drm, int size
>  	return &obj->ttm.base;
>  }
>  
> +void intel_fbdev_fb_bo_destroy(struct drm_gem_object *obj)
> +{
> +	xe_bo_unpin_map_no_vm(gem_to_xe_bo(obj));
> +}
> +
>  struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_device *drm,
>  					       struct drm_mode_fb_cmd2 *mode_cmd)
>  {
> @@ -76,7 +81,7 @@ struct intel_framebuffer *intel_fbdev_fb_alloc(struct drm_device *drm,
>  							  mode_cmd->modifier[0]),
>  				      mode_cmd);
>  	if (IS_ERR(fb)) {
> -		xe_bo_unpin_map_no_vm(gem_to_xe_bo(obj));
> +		intel_fbdev_fb_bo_destroy(obj);
>  		goto err;
>  	}
>  
> -- 
> 2.47.2

-- 
Ville Syrjälä
Intel