[PATCH] drm/sysfb: Clear entire framebuffer in atomic_disable

[PATCH] drm/sysfb: Clear entire framebuffer in atomic_disable

[oushixiong1025]

From: Shixiong Ou <oushixiong@kylinos.cn>

drm_sysfb_plane_helper_atomic_disable() previously used
plane_state->src_* coordinates to construct the clear rectangle,
which depends on user-controlled input. Instead, clear the entire
visible framebuffer region using fb_mode dimensions, and use
drm_format_info_min_pitch() to compute the safe per-line clear size
without touching non-visible bytes at the end of each line.

Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>
---
 drivers/gpu/drm/sysfb/drm_sysfb_modeset.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c b/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
index 9a4c210d6f96..c109ecab9d7a 100644
--- a/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
+++ b/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
@@ -376,28 +376,28 @@ void drm_sysfb_plane_helper_atomic_disable(struct drm_plane *plane,
 	struct drm_device *dev = plane->dev;
 	struct drm_sysfb_device *sysfb = to_drm_sysfb_device(dev);
 	struct iosys_map dst = sysfb->fb_addr;
-	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
 	void __iomem *dst_vmap = dst.vaddr_iomem; /* TODO: Use mapping abstraction */
 	unsigned int dst_pitch = sysfb->fb_pitch;
 	const struct drm_format_info *dst_format = sysfb->fb_format;
 	struct drm_rect dst_clip;
-	unsigned long lines, linepixels, i;
+	unsigned long lines, linepixels, dst_size, i;
 	int idx;
 
-	drm_rect_init(&dst_clip,
-		      plane_state->src_x >> 16, plane_state->src_y >> 16,
-		      plane_state->src_w >> 16, plane_state->src_h >> 16);
+	drm_rect_init(&dst_clip, 0, 0,
+		      sysfb->fb_mode.hdisplay, sysfb->fb_mode.vdisplay);
 
 	lines = drm_rect_height(&dst_clip);
 	linepixels = drm_rect_width(&dst_clip);
+	dst_size = min_t(unsigned long,
+			 drm_format_info_min_pitch(dst_format, 0, linepixels),
+			 dst_pitch);
 
 	if (!drm_dev_enter(dev, &idx))
 		return;
 
 	/* Clear buffer to black if disabled */
-	dst_vmap += drm_fb_clip_offset(dst_pitch, dst_format, &dst_clip);
 	for (i = 0; i < lines; ++i) {
-		memset_io(dst_vmap, 0, linepixels * dst_format->cpp[0]);
+		memset_io(dst_vmap, 0, dst_size);
 		dst_vmap += dst_pitch;
 	}
 
-- 
2.25.1

Re: [PATCH] drm/sysfb: Clear entire framebuffer in atomic_disable

[Thomas Zimmermann]

Hi

Am 26.08.26 um 09:56 schrieb oushixiong1025@163.com:
> From: Shixiong Ou <oushixiong@kylinos.cn>
>
> drm_sysfb_plane_helper_atomic_disable() previously used
> plane_state->src_* coordinates to construct the clear rectangle,
> which depends on user-controlled input. Instead, clear the entire
> visible framebuffer region using fb_mode dimensions, and use
> drm_format_info_min_pitch() to compute the safe per-line clear size
> without touching non-visible bytes at the end of each line.
>
> Signed-off-by: Shixiong Ou <oushixiong@kylinos.cn>

Thank you for implementing the idea. This looks good AFAICT

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>

> ---
>   drivers/gpu/drm/sysfb/drm_sysfb_modeset.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c b/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
> index 9a4c210d6f96..c109ecab9d7a 100644
> --- a/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
> +++ b/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
> @@ -376,28 +376,28 @@ void drm_sysfb_plane_helper_atomic_disable(struct drm_plane *plane,
>   	struct drm_device *dev = plane->dev;
>   	struct drm_sysfb_device *sysfb = to_drm_sysfb_device(dev);
>   	struct iosys_map dst = sysfb->fb_addr;
> -	struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
>   	void __iomem *dst_vmap = dst.vaddr_iomem; /* TODO: Use mapping abstraction */
>   	unsigned int dst_pitch = sysfb->fb_pitch;
>   	const struct drm_format_info *dst_format = sysfb->fb_format;
>   	struct drm_rect dst_clip;
> -	unsigned long lines, linepixels, i;
> +	unsigned long lines, linepixels, dst_size, i;
>   	int idx;
>   
> -	drm_rect_init(&dst_clip,
> -		      plane_state->src_x >> 16, plane_state->src_y >> 16,
> -		      plane_state->src_w >> 16, plane_state->src_h >> 16);
> +	drm_rect_init(&dst_clip, 0, 0,
> +		      sysfb->fb_mode.hdisplay, sysfb->fb_mode.vdisplay);
>   
>   	lines = drm_rect_height(&dst_clip);
>   	linepixels = drm_rect_width(&dst_clip);
> +	dst_size = min_t(unsigned long,
> +			 drm_format_info_min_pitch(dst_format, 0, linepixels),
> +			 dst_pitch);
>   
>   	if (!drm_dev_enter(dev, &idx))
>   		return;
>   
>   	/* Clear buffer to black if disabled */
> -	dst_vmap += drm_fb_clip_offset(dst_pitch, dst_format, &dst_clip);
>   	for (i = 0; i < lines; ++i) {
> -		memset_io(dst_vmap, 0, linepixels * dst_format->cpp[0]);
> +		memset_io(dst_vmap, 0, dst_size);
>   		dst_vmap += dst_pitch;
>   	}
>   

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)