sna/dri2: Apply the paraniod buffer clip in the correct coordinate system

We need to only clip to the extents of the copy in the buffer space -
which implies that we need to translate the region into that space before
doing the clip.

Reported-by: Ilia Mirkin <imirkin@alum.mit.edu>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/src/sna/sna_dri2.c b/src/sna/sna_dri2.c
index 80429eb..000ebcf 100644 (file)
--- a/src/sna/sna_dri2.c
+++ b/src/sna/sna_dri2.c
@@ -867,7 +867,7 @@ __sna_dri2_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
        struct kgem_bo *dst_bo;
        const BoxRec *boxes;
        int16_t dx, dy, sx, sy;
-       int w, h, n;
+       int n;
 
        /* To hide a stale DRI2Buffer, one may choose to substitute
         * pixmap->gpu_bo instead of dst/src->bo, however you then run
@@ -882,23 +882,10 @@ __sna_dri2_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
        assert(is_front(dst->attachment) || is_front(src->attachment));
        assert(dst->attachment != src->attachment);
 
-       /* Copy the minimum of the Drawable / src / dst extents */
-       w = draw->width;
-       if ((src_priv->size & 0xffff) < w)
-               w = src_priv->size & 0xffff;
-       if ((dst_priv->size & 0xffff) < w)
-               w = dst_priv->size & 0xffff;
-
-       h = draw->height;
-       if ((src_priv->size >> 16) < h)
-               h = src_priv->size >> 16;
-       if ((dst_priv->size >> 16) < h)
-               h = dst_priv->size >> 16;
-
        clip.extents.x1 = draw->x;
        clip.extents.y1 = draw->y;
-       clip.extents.x2 = draw->x + w;
-       clip.extents.y2 = draw->y + h;
+       clip.extents.x2 = draw->x + draw->width;
+       clip.extents.y2 = draw->y + draw->height;
        clip.data = NULL;
 
        if (region) {
@@ -968,6 +955,30 @@ __sna_dri2_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
                DBG(("%s: updated FrontLeft src_bo from handle=%d to handle=%d\n",
                     __FUNCTION__, src_priv->bo->handle, src_bo->handle));
                assert(src_bo->refcnt);
+       } else {
+               bool changed = false;
+
+               DBG(("%s: source size %dx%d, region size %dx%d\n",
+                    __FUNCTION__,
+                    src_priv->size & 0xffff, src_priv->size >> 16,
+                    (region ?: &clip)->extents.x2 - (region ?: &clip)->extents.x1,
+                    (region ?: &clip)->extents.y2 - (region ?: &clip)->extents.y1));
+
+               assert(sx + clip.extents.x1 >= 0);
+               assert(sy + clip.extents.y1 >= 0);
+
+               if (sx + clip.extents.x2 > (src_priv->size & 0xffff)) {
+                       clip.extents.x2 = (src_priv->size & 0xffff) - sx;
+                       changed = !!region;
+               }
+
+               if (sy + clip.extents.y2 > (src_priv->size >> 16)) {
+                       clip.extents.y2 = (src_priv->size >> 16) - sy;
+                       changed = !!region;
+               }
+
+               if (changed)
+                       pixman_region_intersect(region, &clip, region);
        }
 
        dst_bo = dst_priv->bo;
@@ -988,8 +999,33 @@ __sna_dri2_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
                DBG(("%s: updated FrontLeft dst_bo from handle=%d to handle=%d\n",
                     __FUNCTION__, dst_priv->bo->handle, dst_bo->handle));
                assert(dst_bo->refcnt);
-       } else
+       } else {
+               bool changed = false;
+
+               DBG(("%s: target size %dx%d, region size %dx%d\n",
+                    __FUNCTION__,
+                    dst_priv->size & 0xffff, dst_priv->size >> 16,
+                    (region ?: &clip)->extents.x2 - (region ?: &clip)->extents.x1,
+                    (region ?: &clip)->extents.y2 - (region ?: &clip)->extents.y1));
+
+               assert(dx + clip.extents.x1 >= 0);
+               assert(dy + clip.extents.y1 >= 0);
+
+               if (dx + clip.extents.x2 > (dst_priv->size & 0xffff)) {
+                       clip.extents.x2 = (dst_priv->size & 0xffff) - dx;
+                       changed = !!region;
+               }
+
+               if (dy + clip.extents.y2 > (dst_priv->size >> 16)) {
+                       clip.extents.y2 = (dst_priv->size >> 16) - dy;
+                       changed = !!region;
+               }
+
+               if (changed)
+                       pixman_region_intersect(region, &clip, region);
+
                sync = false;
+       }
 
        if (!wedged(sna)) {
                xf86CrtcPtr crtc;