From 80fda03fc8b5cd09c3e0e90725ef9bcb2a5c7b30 Mon Sep 17 00:00:00 2001 From: Michael Buesch Date: Sun, 28 Oct 2007 17:27:10 +0100 Subject: [PATCH] b43: Fix rfkill callback deadlock wl->mutex might already be locked on initialization. Signed-off-by: Michael Buesch Signed-off-by: John W. Linville --- drivers/net/wireless/b43/rfkill.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/b43/rfkill.c b/drivers/net/wireless/b43/rfkill.c index 800e0a61a7..456930ffef 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); -- 2.39.5