[PATCH] pcmcia/pccard deadlock fix

[Markus Rechberger]

following patch prevents a mutex/semaphore deadlock within the pcmcia
framework when ejecting devices multiple times using pccardctl eject.

For some more details see:
http://lkml.org/lkml/2007/2/19/58

Signed-off-by: Markus Rechberger <markus.rechberger@xxxxxxx>

-- 
Markus Rechberger
Operating System Research Center
AMD Saxony LLC & Co. KG

index ac00424..c02bf0d 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -856,7 +856,8 @@ int pcmcia_eject_card(struct pcmcia_socket *skt)
     
 	cs_dbg(skt, 1, "user eject request\n");
 
-	mutex_lock(&skt->skt_mutex);
+	if (!mutex_trylock(&skt->skt_mutex)) 
+		return -EAGAIN;
 	do {
 		if (!(skt->state & SOCKET_PRESENT)) {
 			ret = -ENODEV;
index 18e111e..b9d3440 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -1100,7 +1100,9 @@ static ssize_t pcmcia_store_allow_func_id_match(struct device *dev,
 	if (!count)
 		return -EINVAL;
 
-	mutex_lock(&p_dev->socket->skt_mutex);
+	if (!mutex_trylock(&p_dev->socket->skt_mutex)) 
+		return -EAGAIN;
+
 	p_dev->allow_func_id_match = 1;
 	mutex_unlock(&p_dev->socket->skt_mutex);