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, 11 deletions

diff --git a/drivers/char/epca.c b/drivers/char/epca.c
index 37d4dca5a5d..39c6a36e395 100644
--- a/drivers/char/epca.c
+++ b/drivers/char/epca.c
@@ -157,7 +157,6 @@ static void epca_error(int, char *);
 static void pc_close(struct tty_struct *, struct file *);
 static void shutdown(struct channel *);
 static void pc_hangup(struct tty_struct *);
-static void pc_put_char(struct tty_struct *, unsigned char);
 static int pc_write_room(struct tty_struct *);
 static int pc_chars_in_buffer(struct tty_struct *);
 static void pc_flush_buffer(struct tty_struct *);
@@ -459,8 +458,7 @@ static void pc_close(struct tty_struct *tty, struct file *filp)
                         setup_empty_event(tty, ch);
                         tty_wait_until_sent(tty, 3000); /* 30 seconds timeout */
                 }
-                if (tty->driver->flush_buffer)
-                        tty->driver->flush_buffer(tty);
+                pc_flush_buffer(tty);
 
                 tty_ldisc_flush(tty);
                 shutdown(ch);
@@ -532,8 +530,7 @@ static void pc_hangup(struct tty_struct *tty)
         if ((ch = verifyChannel(tty)) != NULL) {
                 unsigned long flags;
 
-                if (tty->driver->flush_buffer)
-                        tty->driver->flush_buffer(tty);
+                pc_flush_buffer(tty);
                 tty_ldisc_flush(tty);
                 shutdown(ch);
 
@@ -645,11 +642,6 @@ static int pc_write(struct tty_struct *tty,
         return amountCopied;
 }
 
-static void pc_put_char(struct tty_struct *tty, unsigned char c)
-{
-        pc_write(tty, &c, 1);
-}
-
 static int pc_write_room(struct tty_struct *tty)
 {
         int remain;
@@ -1035,7 +1027,6 @@ static const struct tty_operations pc_ops = {
         .flush_buffer = pc_flush_buffer,
         .chars_in_buffer = pc_chars_in_buffer,
         .flush_chars = pc_flush_chars,
-        .put_char = pc_put_char,
         .ioctl = pc_ioctl,
         .set_termios = pc_set_termios,
         .stop = pc_stop,