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/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
index 0d80fa5..48ed5fd 100644
--- a/drivers/net/ppp_synctty.c
+++ b/drivers/net/ppp_synctty.c
@@ -207,6 +207,9 @@
struct syncppp *ap;
int err;
+ if (tty->ops->write == NULL)
+ return -EOPNOTSUPP;
+
ap = kzalloc(sizeof(*ap), GFP_KERNEL);
err = -ENOMEM;
if (!ap)
@@ -399,8 +402,8 @@
tasklet_schedule(&ap->tsk);
sp_put(ap);
if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
- && tty->driver->unthrottle)
- tty->driver->unthrottle(tty);
+ && tty->ops->unthrottle)
+ tty->ops->unthrottle(tty);
}
static void
@@ -653,7 +656,7 @@
tty_stuffed = 0;
if (!tty_stuffed && ap->tpkt) {
set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
- sent = tty->driver->write(tty, ap->tpkt->data, ap->tpkt->len);
+ sent = tty->ops->write(tty, ap->tpkt->data, ap->tpkt->len);
if (sent < 0)
goto flush; /* error, e.g. loss of CD */
if (sent < ap->tpkt->len) {