commit 32b249b0f54fb304c5f90be00ebcb9c1a32d415c
author Malcolm Priestley <tvboxspy@gmail.com> Mon Apr 06 21:19:48 2015 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Thu Apr 30 16:57:32 2015 +0200
tree 0fe742df27935e5c16e739fee2e07bff20eab5d9
parent aeda3b2d4a6760bda799feeaac391a7bdcdbbdb5

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>

drivers/staging/vt6655/device_main.c

diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c
index 4bb4f8e..5b3de43 100644
--- a/drivers/staging/vt6655/device_main.c
+++ b/drivers/staging/vt6655/device_main.c
@@ -1090,7 +1090,7 @@
 	 * 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 @@
 		}
 
 		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 @@
 			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);