mm: Flag documentation in libdrm. Validation sequence numbers in mm blocks

    so that we can evict a buffer before it's validation sequence wraps
    around. (Every 100th day or so :))

1 files changed, 9 insertions, 4 deletions

diff --git a/libdrm/xf86mm.c b/libdrm/xf86mm.c
index 0b670b53..adb3be89 100644
--- a/libdrm/xf86mm.c
+++ b/libdrm/xf86mm.c
@@ -257,10 +257,6 @@ drmWaitFence(int drmFD, drmFence fence)
 	    fence.fenceSeq) < DRM_MM_WRAP)
 	return 0;
 
-    arg.req.op = wait_fence;
-    arg.req.fence_type = fence.fenceType;
-    arg.req.fence_seq = fence.fenceSeq;
-
     /*
      * Ugly, but necessary for multiple DRI clients with the userspace
      * arbitration scheme. We need a scheduler!!.
@@ -268,6 +264,15 @@ drmWaitFence(int drmFD, drmFence fence)
 
     sched_yield();
 
+    if ((drmMMKI.sarea->retired[fence.fenceType & DRM_FENCE_MASK] -
+	    fence.fenceSeq) < DRM_MM_WRAP)
+	return 0;
+
+    arg.req.op = wait_fence;
+    arg.req.fence_type = fence.fenceType;
+    arg.req.fence_seq = fence.fenceSeq;
+
+
     if (ioctl(drmFD, DRM_IOCTL_FENCE, &arg)) {
 	drmMsg("drmWaitFence: failed: %s\n", strerror(errno));