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>
This commit is contained in:
Alan Cox
2008-04-30 00:54:13 -07:00
committed by Linus Torvalds
parent 251b8dd7ee
commit f34d7a5b70
30 changed files with 539 additions and 666 deletions

View File

@@ -1140,28 +1140,29 @@ static int isicom_write(struct tty_struct *tty, const unsigned char *buf,
}
/* put_char et all */
static void isicom_put_char(struct tty_struct *tty, unsigned char ch)
static int isicom_put_char(struct tty_struct *tty, unsigned char ch)
{
struct isi_port *port = tty->driver_data;
struct isi_board *card = port->card;
unsigned long flags;
if (isicom_paranoia_check(port, tty->name, "isicom_put_char"))
return;
return 0;
if (!port->xmit_buf)
return;
return 0;
spin_lock_irqsave(&card->card_lock, flags);
if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1)
goto out;
if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
spin_unlock_irqrestore(&card->card_lock, flags);
return 0;
}
port->xmit_buf[port->xmit_head++] = ch;
port->xmit_head &= (SERIAL_XMIT_SIZE - 1);
port->xmit_cnt++;
spin_unlock_irqrestore(&card->card_lock, flags);
out:
return;
return 1;
}
/* flush_chars et all */