Patch "drm/vmwgfx: Fix an incorrect lock check" has been added to the 4.4-stable tree

Patch "drm/vmwgfx: Fix an incorrect lock check" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/vmwgfx: Fix an incorrect lock check

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-vmwgfx-fix-an-incorrect-lock-check.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From fb89ac5102ae2875d685c847e6b5dbc141622d43 Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thellstrom@vmware.com>
Date: Fri, 8 Jan 2016 20:29:39 +0100
Subject: drm/vmwgfx: Fix an incorrect lock check

From: Thomas Hellstrom <thellstrom@vmware.com>

commit fb89ac5102ae2875d685c847e6b5dbc141622d43 upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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(str
 {
 	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);


Patches currently in stable-queue which might be from thellstrom@vmware.com are

queue-4.4/drm-vmwgfx-respect-nomodeset.patch
queue-4.4/drm-vmwgfx-fix-an-incorrect-lock-check.patch
queue-4.4/drm-vmwgfx-fix-a-width-pitch-mismatch-on-framebuffer-updates.patch