xf86-video-intel: src/sna/sna_dri.c

[Chris Wilson]

 src/sna/sna_dri.c |   73 ++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 46 insertions(+), 27 deletions(-)

New commits:
commit 5751b9f1f5beb943db8cb5d260379ae39eb18db4
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Mon Jul 29 14:44:51 2013 +0100

    sna/dri: Prevent stale DRI buffers from a NULL dereference
    
    If the DRI buffer is stale, the drawable may have been recreated and no
    longer be associated with DRI. In this case, the pixmap may not be on
    the GPU, so just subsitute the client's old bo and hope the it catches
    up and does a GetBuffers in the near future.
    
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

diff --git a/src/sna/sna_dri.c b/src/sna/sna_dri.c
index b6a605b..8d0b424 100644
--- a/src/sna/sna_dri.c
+++ b/src/sna/sna_dri.c
@@ -672,20 +672,15 @@ __sna_dri_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
 	 * the risk of copying around invalid data. So either you may not
 	 * see the results of the copy, or you may see the wrong pixels.
 	 * Either way you eventually lose.
+	 *
+	 * We also have to be careful in case that the stale buffers are
+	 * now attached to invalid (non-DRI) pixmaps.
 	 */
 
 	assert(dst->attachment == DRI2BufferFrontLeft ||
 	       src->attachment == DRI2BufferFrontLeft);
 	assert(dst->attachment != src->attachment);
 
-	src_bo = src_priv->bo;
-	if (src->attachment == DRI2BufferFrontLeft)
-		src_bo = sna_pixmap_get_bo(pixmap);
-
-	dst_bo = dst_priv->bo;
-	if (dst->attachment == DRI2BufferFrontLeft)
-		dst_bo = sna_pixmap_get_bo(pixmap);
-
 	/* Copy the minimum of the Drawable / src / dst extents */
 	w = draw->width;
 	if ((src_priv->size & 0xffff) < w)
@@ -717,16 +712,6 @@ __sna_dri_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
 		return NULL;
 	}
 
-	if (!wedged(sna)) {
-		if (dst->attachment != DRI2BufferFrontLeft)
-			sync = false;
-		if (sync)
-			sync = sna_pixmap_is_scanout(sna, pixmap);
-
-		sna_dri_select_mode(sna, dst_bo, src_bo, sync);
-	} else
-		sync = false;
-
 	sx = sy = dx = dy = 0;
 	if (dst->attachment == DRI2BufferFrontLeft) {
 		sx = -draw->x;
@@ -756,15 +741,6 @@ __sna_dri_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
 			region = &clip;
 		}
 
-		if (sync) {
-			xf86CrtcPtr crtc;
-
-			crtc = sna_covering_crtc(sna->scrn, &clip.extents, NULL);
-			sync = crtc &&
-				sna_wait_for_scanline(sna, pixmap, crtc,
-						&clip.extents);
-		}
-
 		if (get_drawable_deltas(draw, pixmap, &tx, &ty)) {
 			if (dst->attachment == DRI2BufferFrontLeft) {
 				pixman_region_translate(region ?: &clip, tx, ty);
@@ -775,7 +751,50 @@ __sna_dri_copy_region(struct sna *sna, DrawablePtr draw, RegionPtr region,
 				sy += ty;
 			}
 		}
+	} else
+		sync = false;
+
+	src_bo = src_priv->bo;
+	if (src->attachment == DRI2BufferFrontLeft) {
+		struct sna_pixmap *priv;
+
+		priv = sna_pixmap_move_to_gpu(pixmap, MOVE_READ);
+		if (priv)
+			src_bo = priv->gpu_bo;
 	}
+
+	dst_bo = dst_priv->bo;
+	if (dst->attachment == DRI2BufferFrontLeft) {
+		struct sna_pixmap *priv;
+		unsigned int flags;
+
+		flags = MOVE_WRITE;
+		if (clip.data ||
+		    clip.extents.x1 > 0 ||
+		    clip.extents.x2 < pixmap->drawable.width ||
+		    clip.extents.y1 > 0 ||
+		    clip.extents.y2 < pixmap->drawable.height)
+			flags |= MOVE_READ;
+
+		priv = sna_pixmap_move_to_gpu(pixmap, flags);
+		if (priv)
+			dst_bo = priv->gpu_bo;
+	} else
+		sync = false;
+
+	if (!wedged(sna)) {
+		xf86CrtcPtr crtc;
+
+		crtc = NULL;
+		if (sync && sna_pixmap_is_scanout(sna, pixmap))
+			crtc = sna_covering_crtc(sna->scrn, &clip.extents, NULL);
+		sna_dri_select_mode(sna, dst_bo, src_bo, crtc != NULL);
+
+		sync = (crtc != NULL&&
+			sna_wait_for_scanline(sna, pixmap, crtc,
+					      &clip.extents));
+	}
+
 	if (dst->attachment == DRI2BufferFrontLeft)
 		damage(pixmap, region);
 	if (region) {