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>

3 files changed, 53 insertions, 26 deletions

diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c
index a449449e301c..db53db91ae4a 100644
--- a/drivers/char/isicom.c
+++ b/drivers/char/isicom.c
@@ -841,7 +841,6 @@ static int isicom_carrier_raised(struct tty_port *port)
 static int block_til_ready(struct tty_struct *tty, struct file *filp,
         struct isi_port *ip)
 {
-        struct isi_board *card = ip->card;
         struct tty_port *port = &ip->port;
         int do_clocal = 0, retval;
         unsigned long flags;
@@ -876,11 +875,11 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
         retval = 0;
         add_wait_queue(&port->open_wait, &wait);
 
-        spin_lock_irqsave(&card->card_lock, flags);
+        spin_lock_irqsave(&port->lock, flags);
         if (!tty_hung_up_p(filp))
                 port->count--;
         port->blocked_open++;
-        spin_unlock_irqrestore(&card->card_lock, flags);
+        spin_unlock_irqrestore(&port->lock, flags);
 
         while (1) {
                 tty_port_raise_dtr_rts(port);
@@ -905,14 +904,13 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
         }
         set_current_state(TASK_RUNNING);
         remove_wait_queue(&port->open_wait, &wait);
-        spin_lock_irqsave(&card->card_lock, flags);
+        spin_lock_irqsave(&port->lock, flags);
         if (!tty_hung_up_p(filp))
                 port->count++;
         port->blocked_open--;
-        spin_unlock_irqrestore(&card->card_lock, flags);
-        if (retval)
-                return retval;
-        port->flags |= ASYNC_NORMAL_ACTIVE;
+        if (retval == 0)
+                port->flags |= ASYNC_NORMAL_ACTIVE;
+        spin_unlock_irqrestore(&port->lock, flags);
         return 0;
 }
 
@@ -1034,9 +1032,9 @@ static void isicom_close(struct tty_struct *tty, struct file *filp)
 
         pr_dbg("Close start!!!.\n");
 
-        spin_lock_irqsave(&card->card_lock, flags);
+        spin_lock_irqsave(&port->port.lock, flags);
         if (tty_hung_up_p(filp)) {
-                spin_unlock_irqrestore(&card->card_lock, flags);
+                spin_unlock_irqrestore(&port->port.lock, flags);
                 return;
         }
 
@@ -1054,12 +1052,12 @@ static void isicom_close(struct tty_struct *tty, struct file *filp)
         }
 
         if (port->port.count) {
-                spin_unlock_irqrestore(&card->card_lock, flags);
+                spin_unlock_irqrestore(&port->port.lock, flags);
                 return;
         }
         port->port.flags |= ASYNC_CLOSING;
         tty->closing = 1;
-        spin_unlock_irqrestore(&card->card_lock, flags);
+        spin_unlock_irqrestore(&port->port.lock, flags);
 
         if (port->port.closing_wait != ASYNC_CLOSING_WAIT_NONE)
                 tty_wait_until_sent(tty, port->port.closing_wait);
@@ -1076,22 +1074,22 @@ static void isicom_close(struct tty_struct *tty, struct file *filp)
         isicom_flush_buffer(tty);
         tty_ldisc_flush(tty);
 
-        spin_lock_irqsave(&card->card_lock, flags);
+        spin_lock_irqsave(&port->port.lock, flags);
         tty->closing = 0;
 
         if (port->port.blocked_open) {
-                spin_unlock_irqrestore(&card->card_lock, flags);
+                spin_unlock_irqrestore(&port->port.lock, flags);
                 if (port->port.close_delay) {
                         pr_dbg("scheduling until time out.\n");
                         msleep_interruptible(
                                 jiffies_to_msecs(port->port.close_delay));
                 }
-                spin_lock_irqsave(&card->card_lock, flags);
+                spin_lock_irqsave(&port->port.lock, flags);
                 wake_up_interruptible(&port->port.open_wait);
         }
         port->port.flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_CLOSING);
         wake_up_interruptible(&port->port.close_wait);
-        spin_unlock_irqrestore(&card->card_lock, flags);
+        spin_unlock_irqrestore(&port->port.lock, flags);
 }
 
 /* write et all */
@@ -1430,10 +1428,7 @@ static void isicom_hangup(struct tty_struct *tty)
         isicom_shutdown_port(port);
         spin_unlock_irqrestore(&port->card->card_lock, flags);
 
-        port->port.count = 0;
-        port->port.flags &= ~ASYNC_NORMAL_ACTIVE;
-        tty_port_tty_set(&port->port, NULL);
-        wake_up_interruptible(&port->port.open_wait);
+        tty_port_hangup(&port->port);
 }
 
 
diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c
index fcf1ec77450d..1f5c21ec4b14 100644
--- a/drivers/char/synclinkmp.c
+++ b/drivers/char/synclinkmp.c
@@ -3331,6 +3331,17 @@ static int carrier_raised(struct tty_port *port)
         return (info->serial_signals & SerialSignal_DCD) ? 1 : 0;
 }
 
+static void raise_dtr_rts(struct tty_port *port)
+{
+        SLMP_INFO *info = container_of(port, SLMP_INFO, port);
+        unsigned long flags;
+
+        spin_lock_irqsave(&info->lock,flags);
+        info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+        set_signals(info);
+        spin_unlock_irqrestore(&info->lock,flags);
+}
+
 /* Block the current process until the specified port is ready to open.
  */
 static int block_til_ready(struct tty_struct *tty, struct file *filp,
@@ -3381,12 +3392,8 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp,
         port->blocked_open++;
 
         while (1) {
-                if ((tty->termios->c_cflag & CBAUD)) {
-                        spin_lock_irqsave(&info->lock,flags);
-                        info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
-                        set_signals(info);
-                        spin_unlock_irqrestore(&info->lock,flags);
-                }
+                if (tty->termios->c_cflag & CBAUD)
+                        tty_port_raise_dtr_rts(port);
 
                 set_current_state(TASK_INTERRUPTIBLE);
 
@@ -3793,6 +3800,7 @@ static void add_device(SLMP_INFO *info)
 
 static const struct tty_port_operations port_ops = {
         .carrier_raised = carrier_raised,
+        .raise_dtr_rts = raise_dtr_rts,
 };
 
 /* Allocate and initialize a device instance structure
diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 0557b6384747..9f418bca4a22 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 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty)
 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
  *