From: Oleksij Rempel <bug-track@xxxxxxxxxxxxxxxxx>
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
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Oleksij Rempel <bug-track@xxxxxxxxxxxxxxxxx>
Tested-by: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
---
drivers/net/wireless/b43/b43.h | 4 ++++
drivers/net/wireless/b43/main.c | 19 ++++++++++++-------
2 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index 67c13af..c06b6cb 100644
--- 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 e4d6dc2..747079b 100644
--- 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;
@@ -5283,6 +5284,7 @@ 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))
@@ -5354,12 +5356,15 @@ 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);
@@ -5430,7 +5435,7 @@ 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. */
--
1.7.9.5
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