isicom: redo locking to use tty port locks
This helps set the basis for moving block_til_ready into common code. We also
introduce a tty_port_hangup helper as this will also be generally needed.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 0557b63..9f418bc 100644
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -7,6 +7,7 @@
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
+#include <linux/serial.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/slab.h>
@@ -96,6 +97,29 @@
EXPORT_SYMBOL(tty_port_tty_set);
/**
+ * tty_port_hangup - hangup helper
+ * @port: tty port
+ *
+ * Perform port level tty hangup flag and count changes. Drop the tty
+ * reference.
+ */
+
+void tty_port_hangup(struct tty_port *port)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ port->count = 0;
+ port->flags &= ~ASYNC_NORMAL_ACTIVE;
+ if (port->tty)
+ tty_kref_put(port->tty);
+ port->tty = NULL;
+ spin_unlock_irqrestore(&port->lock, flags);
+ wake_up_interruptible(&port->open_wait);
+}
+EXPORT_SYMBOL(tty_port_hangup);
+
+/**
* tty_port_carrier_raised - carrier raised check
* @port: tty port
*