staging: vt6655: [BUG] Protect MACvSelectPage1 with lock.

commit 95775d12 upstream.

The device must not flip to page 1 while in interrupt lock causing
loss of connection or dead lock.

Protect from changes to page by adding lock where user can
change the page in CARDvSetRSPINF, vnt_configure and set_channel
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/staging/vt6655/card.c

@@ -670,6 +670,9 @@ void CARDvSetRSPINF(struct vnt_private *pDevice, u8 bb_type)
 {
 	union vnt_phy_field_swap phy;
 	unsigned char byTxRate, byRsvTime;      /* For OFDM */
+	unsigned long flags;
+
+	spin_lock_irqsave(&pDevice->lock, flags);
 
 	/* Set to Page1 */
 	MACvSelectPage1(pDevice->PortOffset);
@@ -767,6 +770,8 @@ void CARDvSetRSPINF(struct vnt_private *pDevice, u8 bb_type)
 	VNSvOutPortW(pDevice->PortOffset + MAC_REG_RSPINF_A_72, MAKEWORD(byTxRate, byRsvTime));
 	/* Set to Page0 */
 	MACvSelectPage0(pDevice->PortOffset);
+
+	spin_unlock_irqrestore(&pDevice->lock, flags);
 }
 
 void CARDvUpdateBasicTopRate(struct vnt_private *pDevice)

drivers/staging/vt6655/channel.c

@@ -210,6 +210,10 @@ bool set_channel(void *pDeviceHandler, unsigned int uConnectionChannel)
 	BBvSoftwareReset(pDevice);
 
 	if (pDevice->byLocalID > REV_ID_VT3253_B1) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&pDevice->lock, flags);
+
 		/* set HW default power register */
 		MACvSelectPage1(pDevice->PortOffset);
 		RFbSetPower(pDevice, RATE_1M, pDevice->byCurrentCh);
@@ -217,6 +221,8 @@ bool set_channel(void *pDeviceHandler, unsigned int uConnectionChannel)
 		RFbSetPower(pDevice, RATE_6M, pDevice->byCurrentCh);
 		VNSvOutPortB(pDevice->PortOffset + MAC_REG_PWROFDM, pDevice->byCurPwr);
 		MACvSelectPage0(pDevice->PortOffset);
+
+		spin_unlock_irqrestore(&pDevice->lock, flags);
 	}
 
 	if (pDevice->byBBType == BB_TYPE_11B)

drivers/staging/vt6655/device_main.c

@@ -1571,6 +1571,10 @@ static void vnt_configure(struct ieee80211_hw *hw,
 
 	if (changed_flags & FIF_ALLMULTI) {
 		if (*total_flags & FIF_ALLMULTI) {
+			unsigned long flags;
+
+			spin_lock_irqsave(&priv->lock, flags);
+
 			if (priv->mc_list_count > 2) {
 				MACvSelectPage1(priv->PortOffset);
 
@@ -1592,6 +1596,8 @@ static void vnt_configure(struct ieee80211_hw *hw,
 				MACvSelectPage0(priv->PortOffset);
 			}
 
+			spin_unlock_irqrestore(&priv->lock, flags);
+
 			rx_mode |= RCR_MULTICAST | RCR_BROADCAST;
 		} else {
 			rx_mode &= ~(RCR_MULTICAST | RCR_BROADCAST);