[Intel-gfx] [PATCH 02/13] drm/fb-helper: don't preserve fb_ops across deferred IO use

[Noralf Trønnes]

Den 27.11.2019 17.31, skrev Jani Nikula:
> Deferred IO now preserves the fb_ops.
> 
> Cc: Noralf Trønnes <noralf at tronnes.org>
> Cc: dri-devel at lists.freedesktop.org
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/drm_fb_helper.c | 18 ++----------------
>  1 file changed, 2 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 0c088ea70ad0..a5a2a538d085 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -1954,7 +1954,6 @@ static int drm_fbdev_fb_release(struct fb_info *info, int user)
>  static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>  {
>  	struct fb_info *fbi = fb_helper->fbdev;
> -	struct fb_ops *fbops = NULL;
>  	void *shadow = NULL;
>  
>  	if (!fb_helper->dev)
> @@ -1963,15 +1962,11 @@ static void drm_fbdev_cleanup(struct drm_fb_helper *fb_helper)
>  	if (fbi && fbi->fbdefio) {
>  		fb_deferred_io_cleanup(fbi);
>  		shadow = fbi->screen_buffer;
> -		fbops = fbi->fbops;
>  	}
>  
>  	drm_fb_helper_fini(fb_helper);
>  
> -	if (shadow) {
> -		vfree(shadow);
> -		kfree(fbops);
> -	}
> +	vfree(shadow);
>  
>  	drm_client_framebuffer_delete(fb_helper->buffer);
>  }
> @@ -2062,23 +2057,14 @@ static int drm_fb_helper_generic_probe(struct drm_fb_helper *fb_helper,
>  	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
>  
>  	if (drm_fbdev_use_shadow_fb(fb_helper)) {
> -		struct fb_ops *fbops;
>  		void *shadow;
>  
> -		/*
> -		 * fb_deferred_io_cleanup() clears &fbops->fb_mmap so a per
> -		 * instance version is necessary.
> -		 */
> -		fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
>  		shadow = vzalloc(fbi->screen_size);
> -		if (!fbops || !shadow) {
> -			kfree(fbops);
> +		if (!shadow) {
>  			vfree(shadow);

This vfree can is a no-op now and can be dropped. With that:

Reviewed-by: Noralf Trønnes <noralf at tronnes.org>

>  			return -ENOMEM;
>  		}
>  
> -		*fbops = *fbi->fbops;
> -		fbi->fbops = fbops;
>  		fbi->screen_buffer = shadow;
>  		fbi->fbdefio = &drm_fbdev_defio;
>  
>