usb_serial: API all change

USB serial likes to use port->tty back pointers for the real work it does and
to do so without any actual locking. Unfortunately when you consider hangup
events, hangup/parallel reopen or even worse hangup followed by parallel close
events the tty->port and port->tty pointers are not guaranteed to be the same
as port->tty is the active tty while tty->port is the port the tty may or
may not still be attached to.

So rework the entire API to pass the tty struct. For console cases we need
to pass both for now. This shows up multiple drivers that immediately crash
with USB console some of which have been fixed in the process.

Longer term we need a proper tty as console abstraction

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 20 deletions

diff --git a/drivers/usb/serial/cyberjack.c b/drivers/usb/serial/cyberjack.c
index c164e2cf275..546178ea6f2 100644
--- a/drivers/usb/serial/cyberjack.c
+++ b/drivers/usb/serial/cyberjack.c
@@ -57,15 +57,18 @@ static int debug;
 #define CYBERJACK_PRODUCT_ID	0x0100
 
 /* Function prototypes */
-static int cyberjack_startup (struct usb_serial *serial);
-static void cyberjack_shutdown (struct usb_serial *serial);
-static int  cyberjack_open (struct usb_serial_port *port, struct file *filp);
-static void cyberjack_close (struct usb_serial_port *port, struct file *filp);
-static int cyberjack_write (struct usb_serial_port *port, const unsigned char *buf, int count);
-static int cyberjack_write_room( struct usb_serial_port *port );
-static void cyberjack_read_int_callback (struct urb *urb);
-static void cyberjack_read_bulk_callback (struct urb *urb);
-static void cyberjack_write_bulk_callback (struct urb *urb);
+static int cyberjack_startup(struct usb_serial *serial);
+static void cyberjack_shutdown(struct usb_serial *serial);
+static int  cyberjack_open(struct tty_struct *tty,
+			struct usb_serial_port *port, struct file *filp);
+static void cyberjack_close(struct tty_struct *tty,
+			struct usb_serial_port *port, struct file *filp);
+static int cyberjack_write(struct tty_struct *tty,
+	struct usb_serial_port *port, const unsigned char *buf, int count);
+static int cyberjack_write_room( struct tty_struct *tty);
+static void cyberjack_read_int_callback(struct urb *urb);
+static void cyberjack_read_bulk_callback(struct urb *urb);
+static void cyberjack_write_bulk_callback(struct urb *urb);
 
 static struct usb_device_id id_table [] = {
 	{ USB_DEVICE(CYBERJACK_VENDOR_ID, CYBERJACK_PRODUCT_ID) },
@@ -111,7 +114,7 @@ struct cyberjack_private {
 };
 
 /* do some startup allocations not currently performed by usb_serial_probe() */
-static int cyberjack_startup (struct usb_serial *serial)
+static int cyberjack_startup(struct usb_serial *serial)
 {
 	struct cyberjack_private *priv;
 	int i;
@@ -145,7 +148,7 @@ static int cyberjack_startup (struct usb_serial *serial)
 	return( 0 );
 }
 
-static void cyberjack_shutdown (struct usb_serial *serial)
+static void cyberjack_shutdown(struct usb_serial *serial)
 {
 	int i;
 	
@@ -159,7 +162,8 @@ static void cyberjack_shutdown (struct usb_serial *serial)
 	}
 }
 	
-static int  cyberjack_open (struct usb_serial_port *port, struct file *filp)
+static int  cyberjack_open(struct tty_struct *tty,
+			struct usb_serial_port *port, struct file *filp)
 {
 	struct cyberjack_private *priv;
 	unsigned long flags;
@@ -174,7 +178,8 @@ static int  cyberjack_open (struct usb_serial_port *port, struct file *filp)
 	 * the data through, otherwise it is scheduled, and with high
 	 * data rates (like with OHCI) data can get lost.
 	 */
-	port->tty->low_latency = 1;
+	if (tty)
+		tty->low_latency = 1;
 
 	priv = usb_get_serial_port_data(port);
 	spin_lock_irqsave(&priv->lock, flags);
@@ -186,7 +191,8 @@ static int  cyberjack_open (struct usb_serial_port *port, struct file *filp)
 	return result;
 }
 
-static void cyberjack_close (struct usb_serial_port *port, struct file *filp)
+static void cyberjack_close(struct tty_struct *tty,
+			struct usb_serial_port *port, struct file *filp)
 {
 	dbg("%s - port %d", __func__, port->number);
 
@@ -197,7 +203,8 @@ static void cyberjack_close (struct usb_serial_port *port, struct file *filp)
 	}
 }
 
-static int cyberjack_write (struct usb_serial_port *port, const unsigned char *buf, int count)
+static int cyberjack_write(struct tty_struct *tty,
+	struct usb_serial_port *port, const unsigned char *buf, int count)
 {
 	struct usb_serial *serial = port->serial;
 	struct cyberjack_private *priv = usb_get_serial_port_data(port);
@@ -292,13 +299,13 @@ static int cyberjack_write (struct usb_serial_port *port, const unsigned char *b
 	return (count);
 } 
 
-static int cyberjack_write_room( struct usb_serial_port *port )
+static int cyberjack_write_room(struct tty_struct *tty)
 {
 	/* FIXME: .... */
 	return CYBERJACK_LOCAL_BUF_SIZE;
 }
 
-static void cyberjack_read_int_callback( struct urb *urb )
+static void cyberjack_read_int_callback(struct urb *urb)
 {
 	struct usb_serial_port *port = urb->context;
 	struct cyberjack_private *priv = usb_get_serial_port_data(port);
@@ -355,7 +362,7 @@ resubmit:
 	dbg("%s - usb_submit_urb(int urb)", __func__);
 }
 
-static void cyberjack_read_bulk_callback (struct urb *urb)
+static void cyberjack_read_bulk_callback(struct urb *urb)
 {
 	struct usb_serial_port *port = urb->context;
 	struct cyberjack_private *priv = usb_get_serial_port_data(port);
@@ -374,7 +381,7 @@ static void cyberjack_read_bulk_callback (struct urb *urb)
 		return;
 	}
 
-	tty = port->tty;
+	tty = port->port.tty;
 	if (!tty) {
 		dbg("%s - ignoring since device not open\n", __func__);
 		return;
@@ -407,7 +414,7 @@ static void cyberjack_read_bulk_callback (struct urb *urb)
 	}
 }
 
-static void cyberjack_write_bulk_callback (struct urb *urb)
+static void cyberjack_write_bulk_callback(struct urb *urb)
 {
 	struct usb_serial_port *port = urb->context;
 	struct cyberjack_private *priv = usb_get_serial_port_data(port);