Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=80fda03fc8b5cd09c3e0e90725ef9bcb2a5c7b30
Commit:     80fda03fc8b5cd09c3e0e90725ef9bcb2a5c7b30
Parent:     ce2d90591fe69ba19076c5d187dfc88ba3318623
Author:     Michael Buesch <[EMAIL PROTECTED]>
AuthorDate: Sun Oct 28 17:27:10 2007 +0100
Committer:  Jeff Garzik <[EMAIL PROTECTED]>
CommitDate: Sat Nov 10 04:25:12 2007 -0500

    b43: Fix rfkill callback deadlock
    
    wl->mutex might already be locked on initialization.
    
    Signed-off-by: Michael Buesch <[EMAIL PROTECTED]>
    Signed-off-by: John W. Linville <[EMAIL PROTECTED]>
---
 drivers/net/wireless/b43/rfkill.c |   14 ++++++++++----
 1 files changed, 10 insertions(+), 4 deletions(-)

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 @@ static void b43_rfkill_poll(struct input_polled_dev 
*poll_dev)
                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 @@ static int b43_rfkill_soft_toggle(void *data, enum 
rfkill_state state)
                        b43_radio_turn_off(dev, 0);
                break;
        }
-
 out_unlock:
        mutex_unlock(&wl->mutex);
 
-
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