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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@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: <linux-serial@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Lance Roy 2018-10-04 00:14:04 -07:00 committed by Greg Kroah-Hartman
parent 817e9bc8cc
commit 8ebfe885c6
1 changed files with 6 additions and 9 deletions
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15
drivers/tty/serial/sn_console.c
View File

@ -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);