tty: The big operations rework

- Operations are now a shared const function block as with most other Linux
  objects

- Introduce wrappers for some optional functions to get consistent behaviour

- Wrap put_char which used to be patched by the tty layer

- Document which functions are needed/optional

- Make put_char report success/fail

- Cache the driver->ops pointer in the tty as tty->ops

- Remove various surplus lock calls we no longer need

- Remove proc_write method as noted by Alexey Dobriyan

- Introduce some missing sanity checks where certain driver/ldisc
  combinations would oops as they didn't check needed methods were present

[akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
[akpm@linux-foundation.org: fix isicom]
[akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
[akpm@linux-foundation.org: fix kgdb]
Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c
index c4f4ca31f7c0..5ef69dcd2588 100644
--- a/drivers/char/ip2/ip2main.c
+++ b/drivers/char/ip2/ip2main.c
@@ -169,7 +169,7 @@ static int Fip_firmware_size;
 static int  ip2_open(PTTY, struct file *);
 static void ip2_close(PTTY, struct file *);
 static int  ip2_write(PTTY, const unsigned char *, int);
-static void ip2_putchar(PTTY, unsigned char);
+static int  ip2_putchar(PTTY, unsigned char);
 static void ip2_flush_chars(PTTY);
 static int  ip2_write_room(PTTY);
 static int  ip2_chars_in_buf(PTTY);
@@ -1616,10 +1616,9 @@ ip2_close( PTTY tty, struct file *pFile )
 
         serviceOutgoingFifo ( pCh->pMyBord );
 
-        if ( tty->driver->flush_buffer ) 
-                tty->driver->flush_buffer(tty);
-        if ( tty->ldisc.flush_buffer )  
-                tty->ldisc.flush_buffer(tty);
+        if ( tty->driver->ops->flush_buffer )
+                tty->driver->ops->flush_buffer(tty);
+        tty_ldisc_flush(tty);
         tty->closing = 0;
         
         pCh->pTTY = NULL;
@@ -1738,7 +1737,7 @@ ip2_write( PTTY tty, const unsigned char *pData, int count)
 /*                                                                            */
 /*                                                                            */
 /******************************************************************************/
-static void
+static int
 ip2_putchar( PTTY tty, unsigned char ch )
 {
         i2ChanStrPtr  pCh = tty->driver_data;
@@ -1753,6 +1752,7 @@ ip2_putchar( PTTY tty, unsigned char ch )
                 ip2_flush_chars( tty );
         } else
                 write_unlock_irqrestore(&pCh->Pbuf_spinlock, flags);
+        return 1;
 
 //      ip2trace (CHANN, ITRC_PUTC, ITRC_RETURN, 1, ch );
 }