linux/drivers/net/ethernet/cisco/enic/enic_api.c
Tony Camuso 8e091340cf enic: fix lockdep around devcmd_lock
We were experiencing occasional "BUG: scheduling while atomic" splats
in our testing. Enabling DEBUG_SPINLOCK and DEBUG_LOCKDEP in the kernel
exposed a lockdep in the enic driver.

enic 0000:0b:00.0 eth2: Link UP

======================================================
[ INFO: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected ]
3.12.0-rc1.x86_64-dbg+ #2 Tainted: GF       W
------------------------------------------------------
NetworkManager/4209 [HC0[0]:SC0[2]:HE1:SE0] is trying to acquire:
(&(&enic->devcmd_lock)->rlock){+.+...}, at: [<ffffffffa026b7e4>] enic_dev_packet_filter+0x44/0x90 [enic]

The fix was to replace spin_lock with spin_lock_bh for the enic
devcmd_lock, so that soft irqs would be disabled while the lock
is held.

Signed-off-by: Sujith Sankar <ssujith@cisco.com>
Signed-off-by: Tony Camuso <tcamuso@redhat.com>
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-23 14:32:19 -07:00

49 lines
1.4 KiB
C

/**
* Copyright 2013 Cisco Systems, Inc. All rights reserved.
*
* This program is free software; you may redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <linux/netdevice.h>
#include <linux/spinlock.h>
#include "vnic_dev.h"
#include "vnic_devcmd.h"
#include "enic_res.h"
#include "enic.h"
#include "enic_api.h"
int enic_api_devcmd_proxy_by_index(struct net_device *netdev, int vf,
enum vnic_devcmd_cmd cmd, u64 *a0, u64 *a1, int wait)
{
int err;
struct enic *enic = netdev_priv(netdev);
struct vnic_dev *vdev = enic->vdev;
spin_lock(&enic->enic_api_lock);
spin_lock_bh(&enic->devcmd_lock);
vnic_dev_cmd_proxy_by_index_start(vdev, vf);
err = vnic_dev_cmd(vdev, cmd, a0, a1, wait);
vnic_dev_cmd_proxy_end(vdev);
spin_unlock_bh(&enic->devcmd_lock);
spin_unlock(&enic->enic_api_lock);
return err;
}
EXPORT_SYMBOL(enic_api_devcmd_proxy_by_index);