From: Malcolm Priestley <tvboxspy@gmail.com>
Date: Mon, 6 Apr 2015 20:19:48 +0000 (+0100)
Subject: staging: vt6655: device_intr check for vif on while loop
X-Git-Tag: firefly_0821_release~176^2~1545^2~987
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=32b249b0f54fb304c5f90be00ebcb9c1a32d415c;p=firefly-linux-kernel-4.4.55.git

staging: vt6655: device_intr check for vif on while loop

vif should never be or go null while in loop.

Fixes race condition where interrupts are late and when
interface is not present.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c
index 4bb4f8ee4132..5b3de43bde99 100644
--- a/drivers/staging/vt6655/device_main.c
+++ b/drivers/staging/vt6655/device_main.c
@@ -1090,7 +1090,7 @@ static  irqreturn_t  device_intr(int irq,  void *dev_instance)
 	 * update ISR counter
 	 */
 	STAvUpdate802_11Counter(&pDevice->s802_11Counter, &pDevice->scStatistic, dwMIBCounter);
-	while (pDevice->dwIsr != 0) {
+	while (pDevice->dwIsr && pDevice->vif) {
 		STAvUpdateIsrStatCounter(&pDevice->scStatistic, pDevice->dwIsr);
 		MACvWriteISR(pDevice->PortOffset, pDevice->dwIsr);
 
@@ -1102,8 +1102,7 @@ static  irqreturn_t  device_intr(int irq,  void *dev_instance)
 		}
 
 		if (pDevice->dwIsr & ISR_TBTT) {
-			if (pDevice->vif &&
-			    pDevice->op_mode != NL80211_IFTYPE_ADHOC)
+			if (pDevice->op_mode != NL80211_IFTYPE_ADHOC)
 				vnt_check_bb_vga(pDevice);
 
 			pDevice->bBeaconSent = false;
@@ -1143,19 +1142,15 @@ static  irqreturn_t  device_intr(int irq,  void *dev_instance)
 			max_count += device_tx_srv(pDevice, TYPE_AC0DMA);
 
 		if (pDevice->dwIsr & ISR_SOFTTIMER1) {
-			if (pDevice->vif) {
-				if (pDevice->vif->bss_conf.enable_beacon)
-					vnt_beacon_make(pDevice, pDevice->vif);
-			}
+			if (pDevice->vif->bss_conf.enable_beacon)
+				vnt_beacon_make(pDevice, pDevice->vif);
 		}
 
 		/* If both buffers available wake the queue */
-		if (pDevice->vif) {
-			if (AVAIL_TD(pDevice, TYPE_TXDMA0) &&
-			    AVAIL_TD(pDevice, TYPE_AC0DMA) &&
-			    ieee80211_queue_stopped(pDevice->hw, 0))
-				ieee80211_wake_queues(pDevice->hw);
-		}
+		if (AVAIL_TD(pDevice, TYPE_TXDMA0) &&
+		    AVAIL_TD(pDevice, TYPE_AC0DMA) &&
+		    ieee80211_queue_stopped(pDevice->hw, 0))
+			ieee80211_wake_queues(pDevice->hw);
 
 		MACvReadISR(pDevice->PortOffset, &pDevice->dwIsr);