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, 2 insertions, 14 deletions

diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index 583356426df..45d8eb5de69 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -503,20 +503,9 @@ static void* mgslpc_get_text_ptr(void)
  * The wrappers maintain line discipline references
  * while calling into the line discipline.
  *
- * ldisc_flush_buffer - flush line discipline receive buffers
  * ldisc_receive_buf  - pass receive data to line discipline
  */
 
-static void ldisc_flush_buffer(struct tty_struct *tty)
-{
-	struct tty_ldisc *ld = tty_ldisc_ref(tty);
-	if (ld) {
-		if (ld->flush_buffer)
-			ld->flush_buffer(tty);
-		tty_ldisc_deref(ld);
-	}
-}
-
 static void ldisc_receive_buf(struct tty_struct *tty,
 			      const __u8 *data, char *flags, int count)
 {
@@ -2467,10 +2456,9 @@ static void mgslpc_close(struct tty_struct *tty, struct file * filp)
  	if (info->flags & ASYNC_INITIALIZED)
  		mgslpc_wait_until_sent(tty, info->timeout);
 
-	if (tty->driver->flush_buffer)
-		tty->driver->flush_buffer(tty);
+	mgslpc_flush_buffer(tty);
 
-	ldisc_flush_buffer(tty);
+	tty_ldisc_flush(tty);
 
 	shutdown(info);