From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964913Ab3BTUQA (ORCPT ); Wed, 20 Feb 2013 15:16:00 -0500 Received: from mailout02.c08.mtsvc.net ([205.186.168.190]:54850 "EHLO mailout02.c08.mtsvc.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935983Ab3BTUPy (ORCPT ); Wed, 20 Feb 2013 15:15:54 -0500 From: Peter Hurley To: Greg Kroah-Hartman , Jiri Slaby Cc: Sasha Levin , Sebastian Andrzej Siewior , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Ilya Zykov , Dave Jones , Michael Ellerman , Shawn Guo , Peter Hurley Subject: [PATCH v4 32/32] tty: Drop "tty is NULL" flip buffer diagnostic Date: Wed, 20 Feb 2013 15:03:19 -0500 Message-Id: <1361390599-15195-33-git-send-email-peter@hurleysoftware.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1361390599-15195-1-git-send-email-peter@hurleysoftware.com> References: <1361390599-15195-1-git-send-email-peter@hurleysoftware.com> In-Reply-To: <1360095638-6624-1-git-send-email-peter@hurleysoftware.com> References: <1360095638-6624-1-git-send-email-peter@hurleysoftware.com> X-Authenticated-User: 125194 peter@hurleysoftware.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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