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From: Peter Hurley <peter@hurleysoftware.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
	linux-kernel@vger.kernel.org,
	Peter Hurley <peter@hurleysoftware.com>
Subject: [PATCH 6/6] n_tty: Remove tty count checks from unthrottle
Date: Sat, 12 Dec 2015 14:16:39 -0800	[thread overview]
Message-ID: <1449958599-5533-7-git-send-email-peter@hurleysoftware.com> (raw)
In-Reply-To: <1449958599-5533-1-git-send-email-peter@hurleysoftware.com>

Since n_tty_check_unthrottle() is only called from n_tty_read()
which only originates from a userspace read(), the tty count cannot
be 0; the read() guarantees the file descriptor has not yet been
released.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
---
 drivers/tty/n_tty.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 5034da0..dd34c5d 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -263,8 +263,6 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
 	if (tty->driver->type == TTY_DRIVER_TYPE_PTY) {
 		if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
 			return;
-		if (!tty->count)
-			return;
 		n_tty_kick_worker(tty);
 		tty_wakeup(tty->link);
 		return;
@@ -283,8 +281,6 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
 		tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE);
 		if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE)
 			break;
-		if (!tty->count)
-			break;
 		n_tty_kick_worker(tty);
 		unthrottled = tty_unthrottle_safe(tty);
 		if (!unthrottled)
-- 
2.6.3


  parent reply	other threads:[~2015-12-12 22:17 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-12 22:16 [PATCH 0/6] More n_tty fixes Peter Hurley
2015-12-12 22:16 ` [PATCH 1/6] n_tty: Always wake up read()/poll() if new input Peter Hurley
2015-12-13 14:49   ` Johannes Stezenbach
2015-12-13 19:53     ` Peter Hurley
2015-12-12 22:16 ` [PATCH 2/6] tty, n_tty: Remove fasync() ldisc notification Peter Hurley
2015-12-12 22:16 ` [PATCH 3/6] tty: Add fasync() hung up file operation Peter Hurley
2015-12-12 22:16 ` [PATCH 4/6] tty: Fix ioctl(FIOASYNC) on hungup file Peter Hurley
2015-12-12 22:16 ` [PATCH 5/6] n_tty: Fix stuck write wakeup Peter Hurley
2015-12-13 15:18   ` Johannes Stezenbach
2015-12-13 18:38     ` Peter Hurley
2015-12-13 19:27       ` Johannes Stezenbach
2015-12-12 22:16 ` Peter Hurley [this message]
2016-01-10  5:45 ` [PATCH v2 0/7] More n_tty fixes Peter Hurley
2016-01-10  5:45   ` [PATCH v2 1/7] n_tty: Always wake up read()/poll() if new input Peter Hurley
2016-01-10  5:45   ` [PATCH v2 2/7] tty, n_tty: Remove fasync() ldisc notification Peter Hurley
2016-01-10  5:45   ` [PATCH v2 3/7] tty: Add fasync() hung up file operation Peter Hurley
2016-01-10  5:45   ` [PATCH v2 4/7] tty: Fix ioctl(FIOASYNC) on hungup file Peter Hurley
2016-01-10  5:45   ` [PATCH v2 5/7] n_tty: Fix stuck write wakeup Peter Hurley
2016-01-10  5:45   ` [PATCH v2 6/7] n_tty: Remove tty count checks from unthrottle Peter Hurley
2016-01-10  5:45   ` [PATCH v2 7/7] tty: n_tty: fix SIGIO for output Peter Hurley

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