Commit 2e351705 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/rect: Keep the scaled clip bounded 



Limit the scaled clip to only clip at most dst_w/h pixels.
This avoids the problem with clip_scaled() not being able
to return negative values. Since new_src_w/h is now properly
bounded we can remove the clamp()s.

Cc: Benjamin Gaignard <benjamin.gaignard@st.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Testcase: igt/kms_selftest/drm_rect_clip_scaled_signed_vs_unsigned
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191122175623.13565-3-ville.syrjala@linux.intel.com


Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: default avatarBenjamin Gaignard <benjamin.gaignard@st.com>
parent 433480c1

drivers/gpu/drm/drm_rect.c

+7 −4
Original line number Diff line number Diff line
@@ -59,6 +59,9 @@ static u32 clip_scaled(u32 src, u32 dst, u32 clip) 
	if (dst == 0)

		return 0;



	/* Only clip what we have. Keeps the result bounded. */

	clip = min(clip, dst);



	tmp = mul_u32_u32(src, dst - clip);



	/*
@@ -94,7 +97,7 @@ bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst, 
		u32 new_src_w = clip_scaled(drm_rect_width(src),

					    drm_rect_width(dst), diff);



		src->x1 = clamp_t(int64_t, src->x2 - new_src_w, INT_MIN, INT_MAX);

		src->x1 = src->x2 - new_src_w;

		dst->x1 = clip->x1;

	}

	diff = clip->y1 - dst->y1;
@@ -102,7 +105,7 @@ bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst, 
		u32 new_src_h = clip_scaled(drm_rect_height(src),

					    drm_rect_height(dst), diff);



		src->y1 = clamp_t(int64_t, src->y2 - new_src_h, INT_MIN, INT_MAX);

		src->y1 = src->y2 - new_src_h;

		dst->y1 = clip->y1;

	}

	diff = dst->x2 - clip->x2;
@@ -110,7 +113,7 @@ bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst, 
		u32 new_src_w = clip_scaled(drm_rect_width(src),

					    drm_rect_width(dst), diff);



		src->x2 = clamp_t(int64_t, src->x1 + new_src_w, INT_MIN, INT_MAX);

		src->x2 = src->x1 + new_src_w;

		dst->x2 = clip->x2;

	}

	diff = dst->y2 - clip->y2;
@@ -118,7 +121,7 @@ bool drm_rect_clip_scaled(struct drm_rect *src, struct drm_rect *dst, 
		u32 new_src_h = clip_scaled(drm_rect_height(src),

					    drm_rect_height(dst), diff);



		src->y2 = clamp_t(int64_t, src->y1 + new_src_h, INT_MIN, INT_MAX);

		src->y2 = src->y1 + new_src_h;

		dst->y2 = clip->y2;

	}

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