staging: vt6656: [bug] Fix missing spin lock in iwctl_siwpower.

Fixes occasional dead lock on power up / down.

spin_lock_irq is used because of unlocking with spin_unlock_irq
elsewhere in the driver.

Only relevant to kernels 3.8 and later when command was
transferred to the iw_handler.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Cc: stable@vger.kernel.org # 3.8+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/staging/vt6656/iwctl.c b/drivers/staging/vt6656/iwctl.c
index c335808211ee..d0cf7d8a20e5 100644
--- a/drivers/staging/vt6656/iwctl.c
+++ b/drivers/staging/vt6656/iwctl.c
@@ -1345,9 +1345,12 @@ int iwctl_siwpower(struct net_device *dev, struct iw_request_info *info,
                 return rc;
         }
 
+        spin_lock_irq(&pDevice->lock);
+
         if (wrq->disabled) {
                 pDevice->ePSMode = WMAC_POWER_CAM;
                 PSvDisablePowerSaving(pDevice);
+                spin_unlock_irq(&pDevice->lock);
                 return rc;
         }
         if ((wrq->flags & IW_POWER_TYPE) == IW_POWER_TIMEOUT) {
@@ -1358,6 +1361,9 @@ int iwctl_siwpower(struct net_device *dev, struct iw_request_info *info,
                 pDevice->ePSMode = WMAC_POWER_FAST;
                 PSvEnablePowerSaving((void *)pDevice, pMgmt->wListenInterval);
         }
+
+        spin_unlock_irq(&pDevice->lock);
+
         switch (wrq->flags & IW_POWER_MODE) {
         case IW_POWER_UNICAST_R:
                 DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO " SIOCSIWPOWER: IW_POWER_UNICAST_R \n");