tty: gigaset: really fix chars_in_buffer

The tty_operation chars_in_buffer() is not allowed to return a negative
value to signal an error.  Corrects the problem flagged by commit
23198fda71, "tty: fix chars_in_buffers".

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Tilman Schmidt 2009-08-06 20:33:33 -07:00 committed by Live-CD User
parent 78f28b7c55
commit a4304f2d5a

View file

@ -408,33 +408,28 @@ static int if_write_room(struct tty_struct *tty)
return retval; return retval;
} }
/* FIXME: This function does not have error returns */
static int if_chars_in_buffer(struct tty_struct *tty) static int if_chars_in_buffer(struct tty_struct *tty)
{ {
struct cardstate *cs; struct cardstate *cs;
int retval = -ENODEV; int retval = 0;
cs = (struct cardstate *) tty->driver_data; cs = (struct cardstate *) tty->driver_data;
if (!cs) { if (!cs) {
pr_err("%s: no cardstate\n", __func__); pr_err("%s: no cardstate\n", __func__);
return -ENODEV; return 0;
} }
gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__); gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);
if (mutex_lock_interruptible(&cs->mutex)) mutex_lock(&cs->mutex);
return -ERESTARTSYS; // FIXME -EINTR?
if (!cs->connected) { if (!cs->connected)
gig_dbg(DEBUG_IF, "not connected"); gig_dbg(DEBUG_IF, "not connected");
retval = -ENODEV; else if (!cs->open_count)
} else if (!cs->open_count)
dev_warn(cs->dev, "%s: device not opened\n", __func__); dev_warn(cs->dev, "%s: device not opened\n", __func__);
else if (cs->mstate != MS_LOCKED) { else if (cs->mstate != MS_LOCKED)
dev_warn(cs->dev, "can't write to unlocked device\n"); dev_warn(cs->dev, "can't write to unlocked device\n");
retval = -EBUSY; else
} else
retval = cs->ops->chars_in_buffer(cs); retval = cs->ops->chars_in_buffer(cs);
mutex_unlock(&cs->mutex); mutex_unlock(&cs->mutex);