From: Thomas Hellstrom <thellstrom@vmware.com>
Date: Fri, 8 Jan 2016 19:29:39 +0000 (+0100)
Subject: drm/vmwgfx: Fix an incorrect lock check
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=fb89ac5102ae2875d685c847e6b5dbc141622d43;p=deliverable%2Flinux.git

drm/vmwgfx: Fix an incorrect lock check

With CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y the vmwgfx kernel module
would unconditionally throw a bug when checking for a held spinlock
in the command buffer code. Fix this by using a lockdep check.

Cc: <stable@vger.kernel.org>
Reported-and-tested-by: Tetsuo Handa <penguin-kernel@i-love-sakura.ne.jp>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c
index 6377e8151000..67cebb23c940 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c
@@ -247,7 +247,7 @@ static void __vmw_cmdbuf_header_free(struct vmw_cmdbuf_header *header)
 {
 	struct vmw_cmdbuf_man *man = header->man;
 
-	BUG_ON(!spin_is_locked(&man->lock));
+	lockdep_assert_held_once(&man->lock);
 
 	if (header->inline_space) {
 		vmw_cmdbuf_header_inline_free(header);