[PATCH] tty: serial: jsm: hold port lock when reporting modem line changes

From: Zheyu Ma
Date: Sat Jul 10 2021 - 10:07:02 EST


uart_handle_dcd_change() requires a port lock to be held and will emit a
warning when lockdep is enabled.

Held corresponding lock to fix warnings.

Signed-off-by: Zheyu Ma <zheyuma97@xxxxxxxxx>
---
drivers/tty/serial/jsm/jsm_neo.c | 2 ++
drivers/tty/serial/jsm/jsm_tty.c | 3 +++
2 files changed, 5 insertions(+)

diff --git a/drivers/tty/serial/jsm/jsm_neo.c b/drivers/tty/serial/jsm/jsm_neo.c
index bf0e2a4cb0ce..c6f927a76c3b 100644
--- a/drivers/tty/serial/jsm/jsm_neo.c
+++ b/drivers/tty/serial/jsm/jsm_neo.c
@@ -815,7 +815,9 @@ static void neo_parse_isr(struct jsm_board *brd, u32 port)
/* Parse any modem signal changes */
jsm_dbg(INTR, &ch->ch_bd->pci_dev,
"MOD_STAT: sending to parse_modem_sigs\n");
+ spin_lock_irqsave(&ch->uart_port.lock, lock_flags);
neo_parse_modem(ch, readb(&ch->ch_neo_uart->msr));
+ spin_unlock_irqrestore(&ch->uart_port.lock, lock_flags);
}
}

diff --git a/drivers/tty/serial/jsm/jsm_tty.c b/drivers/tty/serial/jsm/jsm_tty.c
index 8e42a7682c63..d74cbbbf33c6 100644
--- a/drivers/tty/serial/jsm/jsm_tty.c
+++ b/drivers/tty/serial/jsm/jsm_tty.c
@@ -187,6 +187,7 @@ static void jsm_tty_break(struct uart_port *port, int break_state)

static int jsm_tty_open(struct uart_port *port)
{
+ unsigned long lock_flags;
struct jsm_board *brd;
struct jsm_channel *channel =
container_of(port, struct jsm_channel, uart_port);
@@ -240,6 +241,7 @@ static int jsm_tty_open(struct uart_port *port)
channel->ch_cached_lsr = 0;
channel->ch_stops_sent = 0;

+ spin_lock_irqsave(&port->lock, lock_flags);
termios = &port->state->port.tty->termios;
channel->ch_c_cflag = termios->c_cflag;
channel->ch_c_iflag = termios->c_iflag;
@@ -259,6 +261,7 @@ static int jsm_tty_open(struct uart_port *port)
jsm_carrier(channel);

channel->ch_open_count++;
+ spin_unlock_irqrestore(&port->lock, lock_flags);

jsm_dbg(OPEN, &channel->ch_bd->pci_dev, "finish\n");
return 0;
--
2.17.6