b43: Fix controller restart crash

upstream commit: 3bf0a32e22fedc0b46443699db2d61ac2a883ac4

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>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index e0055d0fa0c894d465ca79220ba3049e15b9ca9b..6966eec666e2c5666e17ff961d73074d90898e00 100644 (file)
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -3818,7 +3818,9 @@ 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");
@@ -3967,9 +3969,11 @@ 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);
@@ -4152,6 +4156,10 @@ 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);