This il->vif is dereferenced in different part of iwlegacy code, so do
not nullify it. This should fix random crashes observed in companion
with microcode errors i.e. crash in il3945_config_ap().

Additionally this should address also
WARNING: at drivers/net/wireless/iwlegacy/common.c:4656 il_mac_remove_interface
at least one of the possible reasons of that warning.

Cc: stable@vger.kernel.org
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
 drivers/net/wireless/iwlegacy/3945-mac.c |    2 --
 drivers/net/wireless/iwlegacy/4965-mac.c |    2 --
 drivers/net/wireless/iwlegacy/common.c   |   15 ++++++++++++---
 3 files changed, 12 insertions(+), 7 deletions(-)

--- linux-3.3.noarch.orig/drivers/net/wireless/iwlegacy/3945-mac.c
+++ linux-3.3.noarch/drivers/net/wireless/iwlegacy/3945-mac.c
@@ -2684,7 +2684,6 @@ il3945_bg_restart(struct work_struct *da
 
 	if (test_and_clear_bit(S_FW_ERROR, &il->status)) {
 		mutex_lock(&il->mutex);
-		il->ctx.vif = NULL;
 		il->is_open = 0;
 		mutex_unlock(&il->mutex);
 		il3945_down(il);
--- linux-3.3.noarch.orig/drivers/net/wireless/iwlegacy/4965-mac.c
+++ linux-3.3.noarch/drivers/net/wireless/iwlegacy/4965-mac.c
@@ -5381,7 +5381,6 @@ il4965_bg_restart(struct work_struct *da
 
 	if (test_and_clear_bit(S_FW_ERROR, &il->status)) {
 		mutex_lock(&il->mutex);
-		il->ctx.vif = NULL;
 		il->is_open = 0;
 
 		__il4965_down(il);
--- linux-3.3.noarch.orig/drivers/net/wireless/iwlegacy/common.c
+++ linux-3.3.noarch/drivers/net/wireless/iwlegacy/common.c
@@ -4575,6 +4575,7 @@ il_mac_add_interface(struct ieee80211_hw
 	struct il_priv *il = hw->priv;
 	struct il_vif_priv *vif_priv = (void *)vif->drv_priv;
 	int err;
+	bool reset;
 	u32 modes;
 
 	D_MAC80211("enter: type %d, addr %pM\n", vif->type, vif->addr);
@@ -4594,6 +4595,16 @@ il_mac_add_interface(struct ieee80211_hw
 		goto out;
 	}
 
+	/*
+	 * We do not support multiple virtual interfaces, but on hardware reset
+	 * we have to add the same interface again.
+	 */
+	reset = (il->ctx.vif == vif);
+	if (il->ctx.vif && !reset) {
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
 	modes = il->ctx.interface_modes | il->ctx.exclusive_interface_modes;
 	if (!(modes & BIT(vif->type))) {
 		err = -EOPNOTSUPP;
@@ -4605,8 +4616,11 @@ il_mac_add_interface(struct ieee80211_hw
 
 	err = il_setup_interface(il, &il->ctx);
 	if (err) {
-		il->ctx.vif = NULL;
-		il->iw_mode = NL80211_IFTYPE_STATION;
+		IL_WARN("Fail to set mode %d\n", vif->type);
+		if (!reset) {
+			il->ctx.vif = NULL;
+			il->iw_mode = NL80211_IFTYPE_STATION;
+		}
 	}
 
 out: