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>
diff --git a/drivers/char/isicom.c b/drivers/char/isicom.c
index 57b1152..9c6be8d 100644
--- a/drivers/char/isicom.c
+++ b/drivers/char/isicom.c
@@ -1140,28 +1140,29 @@
}
/* 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 */