[src/trunk]: src/sys/external/bsd/drm2/ttm ttm_bo_unreserve in case of ttm_bo...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a6704a825184
branches:  trunk
changeset: 809684:a6704a825184
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Tue Jul 28 01:25:00 2015 +0000

description:
ttm_bo_unreserve in case of ttm_bo_uvm_fault_idle restart.

Better chance of fixing PR kern/49862 by avoiding leaking a buffer
ww_mutex lock.

diffstat:

 sys/external/bsd/drm2/ttm/ttm_bo_vm.c |  7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diffs (29 lines):

diff -r 70de57773b2d -r a6704a825184 sys/external/bsd/drm2/ttm/ttm_bo_vm.c
--- a/sys/external/bsd/drm2/ttm/ttm_bo_vm.c     Mon Jul 27 22:26:50 2015 +0000
+++ b/sys/external/bsd/drm2/ttm/ttm_bo_vm.c     Tue Jul 28 01:25:00 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ttm_bo_vm.c,v 1.9 2015/07/27 22:26:50 riastradh Exp $  */
+/*     $NetBSD: ttm_bo_vm.c,v 1.10 2015/07/28 01:25:00 riastradh Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ttm_bo_vm.c,v 1.9 2015/07/27 22:26:50 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ttm_bo_vm.c,v 1.10 2015/07/28 01:25:00 riastradh Exp $");
 
 #include <sys/types.h>
 
@@ -133,8 +133,9 @@
 
        ret = ttm_bo_uvm_fault_idle(bo, ufi);
        if (ret) {
-               /* Unlocks if it restarts.  */
                KASSERT(ret == -ERESTART);
+               /* ttm_bo_uvm_fault_idle calls uvmfault_unlockall for us.  */
+               ttm_bo_unreserve(bo);
                /* XXX errno Linux->NetBSD */
                return -ret;
        }