From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from static-ip-62-75-166-246.inaddr.intergenia.de ([62.75.166.246]:48066 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789AbXJ1Q2W (ORCPT ); Sun, 28 Oct 2007 12:28:22 -0400 From: Michael Buesch To: John Linville Subject: [PATCH] b43: Fix rfkill callback deadlock Date: Sun, 28 Oct 2007 17:27:10 +0100 Cc: Larry Finger , bcm43xx-dev@lists.berlios.de, linux-wireless@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Message-Id: <200710281727.10446.mb@bu3sch.de> (sfid-20071028_162832_939171_EB5C4C6E) Sender: linux-wireless-owner@vger.kernel.org List-ID: wl->mutex might already be locked on initialization. Signed-off-by: Michael Buesch Index: wireless-2.6/drivers/net/wireless/b43/rfkill.c =================================================================== --- wireless-2.6.orig/drivers/net/wireless/b43/rfkill.c 2007-10-27 13:28:16.000000000 +0200 +++ wireless-2.6/drivers/net/wireless/b43/rfkill.c 2007-10-28 17:13:55.000000000 +0100 @@ -61,15 +61,22 @@ static void b43_rfkill_poll(struct input 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 * b43_radio_turn_off(dev, 0); break; } - out_unlock: mutex_unlock(&wl->mutex);