b43: Fix rfkill callback deadlock
wl->mutex might already be locked on initialization.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/rfkill.c b/drivers/net/wireless/b43/rfkill.c
index 800e0a6..456930f 100644
--- a/drivers/net/wireless/b43/rfkill.c
+++ b/drivers/net/wireless/b43/rfkill.c
@@ -61,15 +61,22 @@
mutex_unlock(&wl->mutex);
}
-/* Called when the RFKILL toggled in software.
- * This is called without locking. */
+/* Called when the RFKILL toggled in software. */
static int b43_rfkill_soft_toggle(void *data, enum rfkill_state state)
{
struct b43_wldev *dev = data;
struct b43_wl *wl = dev->wl;
int err = 0;
- mutex_lock(&wl->mutex);
+ /* When RFKILL is registered, it will call back into this callback.
+ * wl->mutex will already be locked when this happens.
+ * So first trylock. On contention check if we are in initialization.
+ * Silently return if that happens to avoid a deadlock. */
+ if (mutex_trylock(&wl->mutex) == 0) {
+ if (b43_status(dev) < B43_STAT_INITIALIZED)
+ return 0;
+ mutex_lock(&wl->mutex);
+ }
if (b43_status(dev) < B43_STAT_INITIALIZED)
goto out_unlock;
@@ -89,7 +96,6 @@
b43_radio_turn_off(dev, 0);
break;
}
-
out_unlock:
mutex_unlock(&wl->mutex);