[PATCH 08/10] drm/fb-helper: Restore damage area upon errors

[Daniel Vetter]

On Mon, Nov 16, 2020 at 09:04:35PM +0100, Thomas Zimmermann wrote:
> If the damage handling fails, restore the damage area. The next invocation
> of the damage worker will then perform the update.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>  drivers/gpu/drm/drm_fb_helper.c | 23 ++++++++++++++++++++---
>  1 file changed, 20 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 2e1a335bafd2..13b65dad2ca8 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -431,11 +431,28 @@ static void drm_fb_helper_damage_work(struct work_struct *work)
>  	if (helper->buffer) {
>  		ret = drm_fb_helper_damage_blit(helper, &clip_copy);
>  		if (ret)
> -			return;
> +			goto err;
>  	}
>  
> -	if (helper->fb->funcs->dirty)
> -		helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
> +	if (helper->fb->funcs->dirty) {
> +		ret = helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, &clip_copy, 1);
> +		if (ret)
> +			goto err;

I think this is unexpected enough that we should put some drm error
printing here I think.
-Daniel

> +	}
> +
> +	return;
> +
> +err:
> +	/*
> +	 * Restore damage clip rectangle on errors. Next instance of damage
> +	 * worker will perform the update.
> +	 */
> +	spin_lock_irqsave(&helper->damage_lock, flags);
> +	clip->x1 = min_t(u32, clip->x1, clip_copy.x1);
> +	clip->y1 = min_t(u32, clip->y1, clip_copy.y1);
> +	clip->x2 = max_t(u32, clip->x2, clip_copy.x2);
> +	clip->y2 = max_t(u32, clip->y2, clip_copy.y2);
> +	spin_unlock_irqrestore(&helper->damage_lock, flags);
>  }
>  
>  /**
> -- 
> 2.29.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch