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

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 the following warnings.

[  132.528648] WARNING: CPU: 5 PID: 11600 at drivers/tty/serial/serial_core.c:3046 uart_handle_dcd_change+0xf4/0x120
[  132.530482] Modules linked in:
[  132.531050] CPU: 5 PID: 11600 Comm: jsm Not tainted 5.14.0-rc1-00003-g7fef2edf7cc7-dirty #31
[  132.535268] RIP: 0010:uart_handle_dcd_change+0xf4/0x120
[  132.557100] Call Trace:
[  132.557562]  ? __free_pages+0x83/0xb0
[  132.558213]  neo_parse_modem+0x156/0x220
[  132.558897]  neo_param+0x399/0x840
[  132.559495]  jsm_tty_open+0x12f/0x2d0
[  132.560131]  uart_startup.part.18+0x153/0x340
[  132.560888]  ? lock_is_held_type+0xe9/0x140
[  132.561660]  uart_port_activate+0x7f/0xe0
[  132.562351]  ? uart_startup.part.18+0x340/0x340
[  132.563003]  tty_port_open+0x8d/0xf0
[  132.563523]  ? uart_set_options+0x1e0/0x1e0
[  132.564125]  uart_open+0x24/0x40
[  132.564604]  tty_open+0x15c/0x630

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Link: https://lore.kernel.org/r/1626242003-3809-1-git-send-email-zheyuma97@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Zheyu Ma 2021-07-14 05:53:23 +00:00 committed by Greg Kroah-Hartman
parent e7b91932f6
commit 240e126c28
2 changed files with 5 additions and 0 deletions
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2
drivers/tty/serial/jsm/jsm_neo.c
View File

@ -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);
}
}

3
drivers/tty/serial/jsm/jsm_tty.c
View File

@ -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;