From c5f4644e6c8ba21666128603e4e92544d3cd740d Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 29 Jun 2005 09:42:38 +0100 Subject: [PATCH] Serial: Adjust serial locking This patch changes the way serial ports are locked when getting modem status. This change is necessary because we will need to atomically read the modem status and take action depending on the CTS status. Signed-off-by: Russell King --- drivers/serial/serial_core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'drivers/serial/serial_core.c') diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 36b1ae083fb..f5ce58d0514 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -828,7 +828,10 @@ static int uart_tiocmget(struct tty_struct *tty, struct file *file) if ((!file || !tty_hung_up_p(file)) && !(tty->flags & (1 << TTY_IO_ERROR))) { result = port->mctrl; + + spin_lock_irq(&port->lock); result |= port->ops->get_mctrl(port); + spin_unlock_irq(&port->lock); } up(&state->sem); @@ -1369,6 +1372,7 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) DECLARE_WAITQUEUE(wait, current); struct uart_info *info = state->info; struct uart_port *port = state->port; + unsigned int mctrl; info->blocked_open++; state->count--; @@ -1416,7 +1420,10 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) * and wait for the carrier to indicate that the * modem is ready for us. */ - if (port->ops->get_mctrl(port) & TIOCM_CAR) + spin_lock_irq(&port->lock); + mctrl = port->ops->get_mctrl(port); + spin_unlock_irq(&port->lock); + if (mctrl & TIOCM_CAR) break; up(&state->sem); @@ -1618,7 +1625,9 @@ static int uart_line_info(char *buf, struct uart_driver *drv, int i) if(capable(CAP_SYS_ADMIN)) { + spin_lock_irq(&port->lock); status = port->ops->get_mctrl(port); + spin_unlock_irq(&port->lock); ret += sprintf(buf + ret, " tx:%d rx:%d", port->icount.tx, port->icount.rx); -- cgit v1.2.2 From 0dd7a1aed7c34a39917c4faf75b4230c169e809b Mon Sep 17 00:00:00 2001 From: Russell King Date: Wed, 29 Jun 2005 18:40:53 +0100 Subject: [PATCH] Serial: Check status of CTS when using flow control Fix bugme #4712: read the CTS status and set hw_stopped if CTS is not active when opening the port and/or enabling CRTSCTS Thanks to Stefan Wolff for spotting this problem. Signed-off-by: Russell King --- drivers/serial/serial_core.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'drivers/serial/serial_core.c') diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index f5ce58d0514..139863a787f 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -182,6 +182,13 @@ static int uart_startup(struct uart_state *state, int init_hw) uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR); } + if (info->flags & UIF_CTS_FLOW) { + spin_lock_irq(&port->lock); + if (!(port->ops->get_mctrl(port) & TIOCM_CTS)) + info->tty->hw_stopped = 1; + spin_unlock_irq(&port->lock); + } + info->flags |= UIF_INITIALIZED; clear_bit(TTY_IO_ERROR, &info->tty->flags); @@ -1134,6 +1141,16 @@ static void uart_set_termios(struct tty_struct *tty, struct termios *old_termios spin_unlock_irqrestore(&state->port->lock, flags); } + /* Handle turning on CRTSCTS */ + if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { + spin_lock_irqsave(&state->port->lock, flags); + if (!(state->port->ops->get_mctrl(state->port) & TIOCM_CTS)) { + tty->hw_stopped = 1; + state->port->ops->stop_tx(state->port, 0); + } + spin_unlock_irqrestore(&state->port->lock, flags); + } + #if 0 /* * No need to wake up processes in open wait, since they -- cgit v1.2.2 From 976ecd12b8144d066a23fe97c6fbfc1ac8470af7 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 3 Jul 2005 21:05:45 +0100 Subject: [PATCH] Serial: Fix console port spinlock initialisation Initialise the spinlock for port being used by the console early, but don't re-initialise it again later. Signed-off-by: Russell King --- drivers/serial/serial_core.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'drivers/serial/serial_core.c') diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 139863a787f..54699c3a00a 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -1808,6 +1808,12 @@ uart_set_options(struct uart_port *port, struct console *co, struct termios termios; int i; + /* + * Ensure that the serial console lock is initialised + * early. + */ + spin_lock_init(&port->lock); + memset(&termios, 0, sizeof(struct termios)); termios.c_cflag = CREAD | HUPCL | CLOCAL; @@ -2196,10 +2202,16 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port) state->port = port; - spin_lock_init(&port->lock); port->cons = drv->cons; port->info = state->info; + /* + * If this port is a console, then the spinlock is already + * initialised. + */ + if (!uart_console(port)) + spin_lock_init(&port->lock); + uart_configure_port(drv, state, port); /* -- cgit v1.2.2