b43: Fix controller restart crash

This fixes a kernel crash on rmmod, in the case where the controller
was restarted before doing the rmmod.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index b8e77751065a..6c3d9ea0a9f8 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -4271,7 +4271,9 @@ static void b43_chip_reset(struct work_struct *work)
                         goto out;
                 }
         }
-      out:
+out:
+        if (err)
+                wl->current_dev = NULL; /* Failed to init the dev. */
         mutex_unlock(&wl->mutex);
         if (err)
                 b43err(wl, "Controller restart FAILED\n");
@@ -4412,9 +4414,11 @@ static void b43_one_core_detach(struct ssb_device *dev)
         struct b43_wldev *wldev;
         struct b43_wl *wl;
 
+        /* Do not cancel ieee80211-workqueue based work here.
+         * See comment in b43_remove(). */
+
         wldev = ssb_get_drvdata(dev);
         wl = wldev->wl;
-        cancel_work_sync(&wldev->restart_work);
         b43_debugfs_remove_device(wldev);
         b43_wireless_core_detach(wldev);
         list_del(&wldev->list);
@@ -4599,6 +4603,10 @@ static void b43_remove(struct ssb_device *dev)
         struct b43_wl *wl = ssb_get_devtypedata(dev);
         struct b43_wldev *wldev = ssb_get_drvdata(dev);
 
+        /* We must cancel any work here before unregistering from ieee80211,
+         * as the ieee80211 unreg will destroy the workqueue. */
+        cancel_work_sync(&wldev->restart_work);
+
         B43_WARN_ON(!wl);
         if (wl->current_dev == wldev)
                 ieee80211_unregister_hw(wl->hw);