diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index a3e7aed7e68075f5418ad83e80217d7f6206d89d..6f377de099f93ad44ec876e6d385ff916b08345a 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -251,22 +251,19 @@ static int radeon_cs_get_ring(struct radeon_cs_parser *p, u32 ring, s32 priority
 
 static int radeon_cs_sync_rings(struct radeon_cs_parser *p)
 {
-	int i, r = 0;
+	struct radeon_cs_reloc *reloc;
+	int r;
 
-	for (i = 0; i < p->nrelocs; i++) {
+	list_for_each_entry(reloc, &p->validated, tv.head) {
 		struct reservation_object *resv;
 
-		if (!p->relocs[i].robj)
-			continue;
-
-		resv = p->relocs[i].robj->tbo.resv;
+		resv = reloc->robj->tbo.resv;
 		r = radeon_semaphore_sync_resv(p->rdev, p->ib.semaphore, resv,
-					       p->relocs[i].tv.shared);
-
+					       reloc->tv.shared);
 		if (r)
-			break;
+			return r;
 	}
-	return r;
+	return 0;
 }
 
 /* XXX: note that this is called from the legacy UMS CS ioctl as well */
diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index 8309b11e674d8506bfeb3f05530407ede4b60642..03586763ee8616ae41d17f91bc4ad6d70ac7f646 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -795,6 +795,8 @@ int radeon_get_vblank_timestamp_kms(struct drm_device *dev, int crtc,
 
 	/* Get associated drm_crtc: */
 	drmcrtc = &rdev->mode_info.crtcs[crtc]->base;
+	if (!drmcrtc)
+		return -EINVAL;
 
 	/* Helper routine in DRM core does all the work: */
 	return drm_calc_vbltimestamp_from_scanoutpos(dev, crtc, max_error,
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index 99a960a4f30265c893a411763843a260d38e6a41..4c0d786d5c7a2a00fde32feeb81370574e494800 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -213,6 +213,13 @@ int radeon_bo_create(struct radeon_device *rdev,
 	if (!(rdev->flags & RADEON_IS_PCIE))
 		bo->flags &= ~(RADEON_GEM_GTT_WC | RADEON_GEM_GTT_UC);
 
+#ifdef CONFIG_X86_32
+	/* XXX: Write-combined CPU mappings of GTT seem broken on 32-bit
+	 * See https://bugs.freedesktop.org/show_bug.cgi?id=84627
+	 */
+	bo->flags &= ~RADEON_GEM_GTT_WC;
+#endif
+
 	radeon_ttm_placement_from_domain(bo, domain);
 	/* Kernel allocation are uninterruptible */
 	down_read(&rdev->pm.mclk_lock);