ser_gigaset: convert mutex to completion
The ser_gigaset ISDN driver was using a mutex in its close() method for
waiting for other running ldisc methods to finish. That's what completions
are for. Incidentally, this also avoids a spurious "BUG: lock held at task
exit time" message when the driver's userspace daemon daemonizes itself.
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/isdn/gigaset/ser-gigaset.c b/drivers/isdn/gigaset/ser-gigaset.c
index f2bb1ae..fceeb1d 100644
--- a/drivers/isdn/gigaset/ser-gigaset.c
+++ b/drivers/isdn/gigaset/ser-gigaset.c
@@ -17,6 +17,7 @@
#include <linux/platform_device.h>
#include <linux/tty.h>
#include <linux/poll.h>
+#include <linux/completion.h>
/* Version Information */
#define DRIVER_AUTHOR "Tilman Schmidt"
@@ -48,7 +49,7 @@
struct platform_device dev;
struct tty_struct *tty;
atomic_t refcnt;
- struct mutex dead_mutex;
+ struct completion dead_cmp;
};
static struct platform_driver device_driver = {
@@ -498,7 +499,7 @@
static void cs_put(struct cardstate *cs)
{
if (atomic_dec_and_test(&cs->hw.ser->refcnt))
- mutex_unlock(&cs->hw.ser->dead_mutex);
+ complete(&cs->hw.ser->dead_cmp);
}
/*
@@ -527,8 +528,8 @@
cs->dev = &cs->hw.ser->dev.dev;
cs->hw.ser->tty = tty;
- mutex_init(&cs->hw.ser->dead_mutex);
atomic_set(&cs->hw.ser->refcnt, 1);
+ init_completion(&cs->hw.ser->dead_cmp);
tty->disc_data = cs;
@@ -543,7 +544,6 @@
}
gig_dbg(DEBUG_INIT, "Startup of HLL done");
- mutex_lock(&cs->hw.ser->dead_mutex);
return 0;
error:
@@ -577,7 +577,7 @@
else {
/* wait for running methods to finish */
if (!atomic_dec_and_test(&cs->hw.ser->refcnt))
- mutex_lock(&cs->hw.ser->dead_mutex);
+ wait_for_completion(&cs->hw.ser->dead_cmp);
}
/* stop operations */