[PATCH v4 32/32] tty: Drop "tty is NULL" flip buffer diagnostic

[Peter Hurley]

Although this warning uncovered a multitude of races and errors
in the tty and ldisc layers, this diagnostic now has too many
false-positives.

An expected outcome of the separation of driver i/o paths from
tty lifetimes (added in 3.9) is that the tty may already be
in advanced stages of teardown when scheduled flip buffer work
runs. Ldisc i/o is prevented in this case because flush_to_ldisc()
cannot acquire an ldisc reference.

Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx>
---
 drivers/tty/tty_buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 0dd35ce..8e8d730 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -425,7 +425,7 @@ static void flush_to_ldisc(struct work_struct *work)
 	struct tty_ldisc *disc;
 
 	tty = port->itty;
-	if (WARN_RATELIMIT(tty == NULL, "tty is NULL\n"))
+	if (tty == NULL)
 		return;
 
 	disc = tty_ldisc_ref(tty);
-- 
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/