[PATCH 01/12] gigaset: really fix chars_in_buffer

Tilman Schmidt
2009-09-18T23:59:08Z

The tty_operation chars_in_buffer() is not allowed to return a
negative value to signal an error. Corrects the problem flagged
by commit 23198fda7182969b619613a555f8645fdc3dc334,
"tty: fix chars_in_buffers".

Impact: error handling bugfix
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
---
drivers/isdn/gigaset/interface.c | 19 +++++++------------
1 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/isdn/gigaset/interface.c b/drivers/isdn/gigaset/interface.c
index 8ff7e35..f33ac27 100644
--- a/drivers/isdn/gigaset/interface.c
+++ b/drivers/isdn/gigaset/interface.c
@@ -408,33 +408,28 @@ static int if_write_room(struct tty_struct *tty)
return retval;
}

-/* FIXME: This function does not have error returns */
-
static int if_chars_in_buffer(struct tty_struct *tty)
{
struct cardstate *cs;
- int retval = -ENODEV;
+ int retval = 0;

cs = (struct cardstate *) tty->driver_data;
if (!cs) {
pr_err("%s: no cardstate\n", __func__);
- return -ENODEV;
+ return 0;
}

gig_dbg(DEBUG_IF, "%u: %s()", cs->minor_index, __func__);

- if (mutex_lock_interruptible(&cs->mutex))
- return -ERESTARTSYS; // FIXME -EINTR?
+ mutex_lock(&cs->mutex);

- if (!cs->connected) {
+ if (!cs->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__);
- else if (cs->mstate != MS_LOCKED) {
+ else if (cs->mstate != MS_LOCKED)
dev_warn(cs->dev, "can't write to unlocked device\n");
- retval = -EBUSY;
- } else
+ else
retval = cs->ops->chars_in_buffer(cs);

mutex_unlock(&cs->mutex);
--
1.6.2.1.214.ge986c