This is a note to let you know that I've just added the patch titled
TTY: sn_console: Replace spin_is_locked() with spin_trylock()
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From 8ebfe885c65ec82a0b1e955cf99ed62664e84414 Mon Sep 17 00:00:00 2001
From: Lance Roy <ldr709@xxxxxxxxx>
Date: Thu, 4 Oct 2018 00:14:04 -0700
Subject: TTY: sn_console: Replace spin_is_locked() with spin_trylock()
sn_sal_console_write() used spin_is_locked() + spin_lock() to get
achieve the same thing as a spin_trylock(), so simplify it by using that
instead. This is also a step towards possibly removing spin_is_locked().
Signed-off-by: Lance Roy <ldr709@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxxx>
Cc: <linux-serial@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/sn_console.c | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/drivers/tty/serial/sn_console.c b/drivers/tty/serial/sn_console.c
index 42b9aded4eb1..fe9170731c16 100644
--- a/drivers/tty/serial/sn_console.c
+++ b/drivers/tty/serial/sn_console.c
@@ -888,7 +888,7 @@ sn_sal_console_write(struct console *co, const char *s, unsigned count)
/* somebody really wants this output, might be an
* oops, kdb, panic, etc. make sure they get it. */
- if (spin_is_locked(&port->sc_port.lock)) {
+ if (!spin_trylock_irqsave(&port->sc_port.lock, flags)) {
int lhead = port->sc_port.state->xmit.head;
int ltail = port->sc_port.state->xmit.tail;
int counter, got_lock = 0;
@@ -905,13 +905,11 @@ sn_sal_console_write(struct console *co, const char *s, unsigned count)
*/
for (counter = 0; counter < 150; mdelay(125), counter++) {
- if (!spin_is_locked(&port->sc_port.lock)
- || stole_lock) {
- if (!stole_lock) {
- spin_lock_irqsave(&port->sc_port.lock,
- flags);
- got_lock = 1;
- }
+ if (stole_lock)
+ break;
+
+ if (spin_trylock_irqsave(&port->sc_port.lock, flags)) {
+ got_lock = 1;
break;
} else {
/* still locked */
@@ -938,7 +936,6 @@ sn_sal_console_write(struct console *co, const char *s, unsigned count)
puts_raw_fixed(port->sc_ops->sal_puts_raw, s, count);
} else {
stole_lock = 0;
- spin_lock_irqsave(&port->sc_port.lock, flags);
sn_transmit_chars(port, 1);
spin_unlock_irqrestore(&port->sc_port.lock, flags);
--
2.19.0
