Thread (2 messages) 2 messages, 2 authors, 2021-07-12

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

From: Jiri Slaby <jirislaby@kernel.org>
Date: 2021-07-12 06:17:44
Also in: lkml

On 10. 07. 21, 16:05, Zheyu Ma wrote:
uart_handle_dcd_change() requires a port lock to be held and will emit a
warning when lockdep is enabled.
Please attach an excerpt from the warning to the commit log.
quoted hunk ↗ jump to hunk
Held corresponding lock to fix warnings.

Signed-off-by: Zheyu Ma <redacted>
---
  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;

-- 
js
suse labs
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