[PATCH 10/12] drm/ast: Fix cursor BO pinning and mapping

[Thomas Zimmermann]

Am 27.01.21 um 13:03 schrieb Thomas Zimmermann:
> GEM vmap operations are not allowed in commit tail. Therefore, we cannot
> map the cursor source BO in atomic_update. Instead do this in prepare_fb.
> There was no pin operation for the BO, so add this as well.

Reviewing drm_gem_vram_vmap() I saw that is pins implicitly. I'll remove 
the pinning from the driver code in the patch's next iteration.

> 
> Hence the cursor source BO is now mapped while it's being displayed. The
> change will allow us to move all cursor damage handling from prepare_fb
> to atomic_update.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
> ---
>   drivers/gpu/drm/ast/ast_mode.c | 37 +++++++++++++++++++++++++++++++---
>   1 file changed, 34 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/ast/ast_mode.c b/drivers/gpu/drm/ast/ast_mode.c
> index 199ad9f9c932..192d3d34b9ed 100644
> --- a/drivers/gpu/drm/ast/ast_mode.c
> +++ b/drivers/gpu/drm/ast/ast_mode.c
> @@ -751,6 +751,10 @@ static void ast_set_cursor_enabled(struct ast_private *ast, bool enabled)
>   
>   struct ast_cursor_plane_state {
>   	struct drm_plane_state base;
> +
> +	/* Transitional state - do not export or duplicate */
> +
> +	struct dma_buf_map map;
>   };
>   
>   static inline struct ast_cursor_plane_state *
> @@ -771,6 +775,7 @@ ast_cursor_plane_helper_prepare_fb(struct drm_plane *plane,
>   	struct drm_framebuffer *fb = new_state->fb;
>   	struct dma_buf_map dst_map =
>   		ast_cursor_plane->hwc[ast_cursor_plane->next_hwc_index].map;
> +	struct ast_cursor_plane_state *new_ast_state = to_ast_cursor_plane_state(new_state);
>   	struct drm_gem_vram_object *src_gbo;
>   	struct dma_buf_map src_map;
>   	void __iomem *dst;
> @@ -782,9 +787,13 @@ ast_cursor_plane_helper_prepare_fb(struct drm_plane *plane,
>   
>   	src_gbo = drm_gem_vram_of_gem(fb->obj[0]);
>   
> -	ret = drm_gem_vram_vmap(src_gbo, &src_map);
> +	ret = drm_gem_vram_pin(src_gbo, 0);
>   	if (ret)
>   		return ret;
> +
> +	ret = drm_gem_vram_vmap(src_gbo, &src_map);
> +	if (ret)
> +		goto err_drm_gem_vram_unpin;
>   	src = src_map.vaddr; /* TODO: Use mapping abstraction properly */
>   
>   	dst = dst_map.vaddr_iomem; /* TODO: Use mapping abstraction properly */
> @@ -792,9 +801,31 @@ ast_cursor_plane_helper_prepare_fb(struct drm_plane *plane,
>   	/* do data transfer to cursor BO */
>   	ast_update_cursor_image(dst, src, fb->width, fb->height);
>   
> -	drm_gem_vram_vunmap(src_gbo, &src_map);
> +	new_ast_state->map = src_map;
>   
>   	return 0;
> +
> +err_drm_gem_vram_unpin:
> +	drm_gem_vram_unpin(src_gbo);
> +	return ret;
> +}
> +
> +static void ast_cursor_plane_helper_cleanup_fb(struct drm_plane *plane,
> +					       struct drm_plane_state *old_state)
> +{
> +	struct ast_cursor_plane_state *old_ast_state = to_ast_cursor_plane_state(old_state);
> +	struct drm_framebuffer *fb = old_state->fb;
> +	struct drm_gem_vram_object *gbo;
> +	struct dma_buf_map map;
> +
> +	if (!fb)
> +		return;
> +
> +	gbo = drm_gem_vram_of_gem(fb->obj[0]);
> +	map = old_ast_state->map;
> +
> +	drm_gem_vram_vunmap(gbo, &map);
> +	drm_gem_vram_unpin(gbo);
>   }
>   
>   static int ast_cursor_plane_helper_atomic_check(struct drm_plane *plane,
> @@ -899,7 +930,7 @@ ast_cursor_plane_helper_atomic_disable(struct drm_plane *plane,
>   
>   static const struct drm_plane_helper_funcs ast_cursor_plane_helper_funcs = {
>   	.prepare_fb = ast_cursor_plane_helper_prepare_fb,
> -	.cleanup_fb = NULL, /* not required for cursor plane */
> +	.cleanup_fb = ast_cursor_plane_helper_cleanup_fb,
>   	.atomic_check = ast_cursor_plane_helper_atomic_check,
>   	.atomic_update = ast_cursor_plane_helper_atomic_update,
>   	.atomic_disable = ast_cursor_plane_helper_atomic_disable,
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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