[PATCH] staging: vt6655: Fix interrupt race condition on device start up.

[Malcolm Priestley]

It appears on some slower systems that the driver can find its way
out of the workqueue while the interrupt is disabled by continuous polling
by it.

Move MACvIntEnable to vnt_interrupt_work so that it is always enabled
on all routes out of vnt_interrupt_process.

Move MACvIntDisable so that the device doesn't keep polling the system
while the workqueue is being processed.

Signed-off-by: Malcolm Priestley <tvboxspy at gmail.com>
CC: stable at vger.kernel.org # v4.2+
---
 drivers/staging/vt6655/device_main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c
index b370985b58a1..83f1a1cf9182 100644
--- a/drivers/staging/vt6655/device_main.c
+++ b/drivers/staging/vt6655/device_main.c
@@ -1033,8 +1033,6 @@ static void vnt_interrupt_process(struct vnt_private *priv)
 		return;
 	}
 
-	MACvIntDisable(priv->PortOffset);
-
 	spin_lock_irqsave(&priv->lock, flags);
 
 	/* Read low level stats */
@@ -1122,8 +1120,6 @@ static void vnt_interrupt_process(struct vnt_private *priv)
 	}
 
 	spin_unlock_irqrestore(&priv->lock, flags);
-
-	MACvIntEnable(priv->PortOffset, IMR_MASK_VALUE);
 }
 
 static void vnt_interrupt_work(struct work_struct *work)
@@ -1133,6 +1129,8 @@ static void vnt_interrupt_work(struct work_struct *work)
 
 	if (priv->vif)
 		vnt_interrupt_process(priv);
+
+	MACvIntEnable(priv->PortOffset, IMR_MASK_VALUE);
 }
 
 static irqreturn_t vnt_interrupt(int irq,  void *arg)
@@ -1142,6 +1140,8 @@ static irqreturn_t vnt_interrupt(int irq,  void *arg)
 	if (priv->vif)
 		schedule_work(&priv->interrupt_work);
 
+	MACvIntDisable(priv->PortOffset);
+
 	return IRQ_HANDLED;
 }
 
-- 
2.20.1