tty/serial: lay the foundations for the next set of reworks

- Stop drivers calling their own flush method indirectly, it obfuscates code
  and it will change soon anyway

- A few more lock_kernel paths temporarily needed in some driver internal
  waiting code

- Remove private put_char method that does a write call for one char - we
  have that anyway

- Most but not yet all of the termios copy under lock fixing (some has other
  dependencies to follow)

- Note a few locking bugs in drivers found in the process

- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
  fix the termios locking

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 19 deletions

diff --git a/drivers/char/riscom8.c b/drivers/char/riscom8.c
index b56e0e04cb4a..a82c2a2d5e6c 100644
--- a/drivers/char/riscom8.c
+++ b/drivers/char/riscom8.c
@@ -1015,6 +1015,24 @@ static int rc_open(struct tty_struct * tty, struct file * filp)
         return 0;
 }
 
+static void rc_flush_buffer(struct tty_struct *tty)
+{
+        struct riscom_port *port = (struct riscom_port *)tty->driver_data;
+        unsigned long flags;
+
+        if (rc_paranoia_check(port, tty->name, "rc_flush_buffer"))
+                return;
+
+        spin_lock_irqsave(&riscom_lock, flags);
+
+        port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
+
+        spin_unlock_irqrestore(&riscom_lock, flags);
+
+        tty_wakeup(tty);
+}
+
+
 static void rc_close(struct tty_struct * tty, struct file * filp)
 {
         struct riscom_port *port = (struct riscom_port *) tty->driver_data;
@@ -1078,8 +1096,7 @@ static void rc_close(struct tty_struct * tty, struct file * filp)
                 }
         }
         rc_shutdown_port(bp, port);
-        if (tty->driver->flush_buffer)
-                tty->driver->flush_buffer(tty);
+        rc_flush_buffer(tty);
         tty_ldisc_flush(tty);
 
         tty->closing = 0;
@@ -1213,23 +1230,6 @@ static int rc_chars_in_buffer(struct tty_struct *tty)
         return port->xmit_cnt;
 }
 
-static void rc_flush_buffer(struct tty_struct *tty)
-{
-        struct riscom_port *port = (struct riscom_port *)tty->driver_data;
-        unsigned long flags;
-                                
-        if (rc_paranoia_check(port, tty->name, "rc_flush_buffer"))
-                return;
-
-        spin_lock_irqsave(&riscom_lock, flags);
-
-        port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
-
-        spin_unlock_irqrestore(&riscom_lock, flags);
-        
-        tty_wakeup(tty);
-}
-
 static int rc_tiocmget(struct tty_struct *tty, struct file *file)
 {
         struct riscom_port *port = (struct riscom_port *)tty->driver_data;