gallium: do not increase ref count of the new throttle fence

A new throttle fence was initialized to 1, and increased by 1
again when it's put in drawable->throttle_fence; the ref was
decreased by 1 when it's removed from drawable->throttle_fence,
and never reached to 0, caused leak.

Fixes: ff77bf5cbf7 ("gallium: simplify throttle implementation")
Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/1949
Signed-off-by: James Xiong <james.xiong@intel.com>
Reported-by: Florian Wesch <fw@info-beamer.com>
Reviewed-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>

diff --git a/src/gallium/state_trackers/dri/dri_drawable.c b/src/gallium/state_trackers/dri/dri_drawable.c
index 6335127952c19955c68671a70925256147a4e4af..42c48b50a82a27d6ac7e47d2349dea1a24dc0434 100644 (file)
--- a/src/gallium/state_trackers/dri/dri_drawable.c
+++ b/src/gallium/state_trackers/dri/dri_drawable.c
@@ -489,9 +489,11 @@ dri_flush(__DRIcontext *cPriv,
       st->flush(st, flush_flags, &new_fence);
 
       /* throttle on the previous fence */
-      if (drawable->throttle_fence)
+      if (drawable->throttle_fence) {
          screen->fence_finish(screen, NULL, drawable->throttle_fence, PIPE_TIMEOUT_INFINITE);
-      screen->fence_reference(screen, &drawable->throttle_fence, new_fence);
+         screen->fence_reference(screen, &drawable->throttle_fence, NULL);
+      }
+      drawable->throttle_fence = new_fence;
    }
    else if (flags & (__DRI2_FLUSH_DRAWABLE | __DRI2_FLUSH_CONTEXT)) {
       st->flush(st, flush_flags, NULL);