From beb1479f6d8f359110ec334a972f979874cd7ad2 Mon Sep 17 00:00:00 2001
From: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Date: Tue, 19 Sep 2023 10:51:54 +0200
Subject: [PATCH] tty: early return from send_break() on
TTY_DRIVER_HARDWARE_BREAK
References: bsc#1214683 (PREEMPT_RT prerequisite backports)
Patch-mainline: v6.6.14
Git-commit: ecf27e4765875ca24ee2fd02edb90290f0e9dd8e
[ Upstream commit 66619686d187b4a6395316b7f39881e945dce4bc ]
If the driver sets TTY_DRIVER_HARDWARE_BREAK, we leave ops->break_ctl()
to the driver and return from send_break(). But we do it using a local
variable and keep the code flowing through the end of the function.
Instead, do 'return' immediately with the ops->break_ctl()'s return
value.
This way, we don't have to stuff the 'else' branch of the 'if' with the
software break handling. And we can re-indent the function too.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230919085156.1578-14-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: 66aad7d8d3ec ("usb: cdc-acm: return correct error code on unsupported break")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
drivers/tty/tty_io.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 383159639f65..92d2da9256ef 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2475,22 +2475,24 @@ static int send_break(struct tty_struct *tty, unsigned int duration)
return 0;
if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK)
- retval = tty->ops->break_ctl(tty, duration);
- else {
- /* Do the work ourselves */
- if (tty_write_lock(tty, false) < 0)
- return -EINTR;
- retval = tty->ops->break_ctl(tty, -1);
- if (retval)
- goto out;
- if (!signal_pending(current))
- msleep_interruptible(duration);
- retval = tty->ops->break_ctl(tty, 0);
+ return tty->ops->break_ctl(tty, duration);
+
+ /* Do the work ourselves */
+ if (tty_write_lock(tty, false) < 0)
+ return -EINTR;
+
+ retval = tty->ops->break_ctl(tty, -1);
+ if (retval)
+ goto out;
+ if (!signal_pending(current))
+ msleep_interruptible(duration);
+ retval = tty->ops->break_ctl(tty, 0);
out:
- tty_write_unlock(tty);
- if (signal_pending(current))
- retval = -EINTR;
- }
+ tty_write_unlock(tty);
+
+ if (signal_pending(current))
+ retval = -EINTR;
+
return retval;
}