b43: do not call ieee80211_unregister_hw if we are not registred

this patch fixes kernel Oops on "rmmod b43" if firmware was not loaded:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000088
IP: [<ffffffff8104e988>] drain_workqueue+0x25/0x142
PGD 153ac6067 PUD 153b82067 PMD 0
Oops: 0000 [#1] SMP

Signed-off-by: Oleksij Rempel <bug-track@fisher-privat.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index 67c13af..c06b6cb 100644 (file)
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -877,6 +877,10 @@ struct b43_wl {
         * from the mac80211 subsystem. */
        u16 mac80211_initially_registered_queues;
 
+       /* Set this if we call ieee80211_register_hw() and check if we call
+        * ieee80211_unregister_hw(). */
+       bool hw_registred;
+
        /* We can only have one operating interface (802.11 core)
         * at a time. General information about this interface follows.
         */

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 5a39b22..acd03a4 100644 (file)
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -2437,6 +2437,7 @@ start_ieee80211:
        err = ieee80211_register_hw(wl->hw);
        if (err)
                goto err_one_core_detach;
+       wl->hw_registred = true;
        b43_leds_register(wl->current_dev);
        goto out;
 
@@ -5299,6 +5300,7 @@ static struct b43_wl *b43_wireless_init(struct b43_bus_dev *dev)
 
        hw->queues = modparam_qos ? B43_QOS_QUEUE_NUM : 1;
        wl->mac80211_initially_registered_queues = hw->queues;
+       wl->hw_registred = false;
        hw->max_rates = 2;
        SET_IEEE80211_DEV(hw, dev->dev);
        if (is_valid_ether_addr(sprom->et1mac))
@@ -5370,12 +5372,15 @@ static void b43_bcma_remove(struct bcma_device *core)
         * as the ieee80211 unreg will destroy the workqueue. */
        cancel_work_sync(&wldev->restart_work);
 
-       /* Restore the queues count before unregistering, because firmware detect
-        * might have modified it. Restoring is important, so the networking
-        * stack can properly free resources. */
-       wl->hw->queues = wl->mac80211_initially_registered_queues;
-       b43_leds_stop(wldev);
-       ieee80211_unregister_hw(wl->hw);
+       B43_WARN_ON(!wl);
+       if (wl->current_dev == wldev && wl->hw_registred) {
+               /* Restore the queues count before unregistering, because firmware detect
+                * might have modified it. Restoring is important, so the networking
+                * stack can properly free resources. */
+               wl->hw->queues = wl->mac80211_initially_registered_queues;
+               b43_leds_stop(wldev);
+               ieee80211_unregister_hw(wl->hw);
+       }
 
        b43_one_core_detach(wldev->dev);
 
@@ -5446,7 +5451,7 @@ static void b43_ssb_remove(struct ssb_device *sdev)
        cancel_work_sync(&wldev->restart_work);
 
        B43_WARN_ON(!wl);
-       if (wl->current_dev == wldev) {
+       if (wl->current_dev == wldev && wl->hw_registred) {
                /* Restore the queues count before unregistering, because firmware detect
                 * might have modified it. Restoring is important, so the networking
                 * stack can properly free resources. */