From bd737f8738b7e15930aa7b47c94c28a8d83148ac Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Delgado Date: Thu, 6 Nov 2014 09:23:00 +0100 Subject: [PATCH] tty/serial_core: Introduce lock mechanism for RS485 Introduce an homogeneous lock system between setting and using the rs485 data of the uart_port. This patch should not be split into multiple ones in order to avoid leaving the tree in an unstable state. Acked-by: Nicolas Ferre Reviewed-by: Alan Cox Suggested-by: Alan Cox Cc: Nicolas Ferre Cc: Jiri Slaby Cc: One Thousand Gnomes Signed-off-by: Ricardo Ribalda Delgado Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/atmel_serial.c | 10 ++++------ drivers/tty/serial/mcf.c | 5 +---- drivers/tty/serial/omap-serial.c | 3 --- drivers/tty/serial/serial_core.c | 13 ++++++++++++- 4 files changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 80c4bfcff3fa..2cb04137ae78 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -294,9 +294,6 @@ static int atmel_config_rs485(struct uart_port *port, { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int mode; - unsigned long flags; - - spin_lock_irqsave(&port->lock, flags); /* Disable interrupts */ UART_PUT_IDR(port, atmel_port->tx_done_mask); @@ -327,8 +324,6 @@ static int atmel_config_rs485(struct uart_port *port, /* Enable interrupts */ UART_PUT_IER(port, atmel_port->tx_done_mask); - spin_unlock_irqrestore(&port->lock, flags); - return 0; } @@ -2533,6 +2528,7 @@ static int atmel_serial_probe(struct platform_device *pdev) struct atmel_uart_data *pdata = dev_get_platdata(&pdev->dev); void *data; int ret = -ENODEV; + bool rs485_enabled; BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1)); @@ -2580,6 +2576,8 @@ static int atmel_serial_probe(struct platform_device *pdev) port->rx_ring.buf = data; } + rs485_enabled = port->uart.rs485.flags & SER_RS485_ENABLED; + ret = uart_add_one_port(&atmel_uart, &port->uart); if (ret) goto err_add_port; @@ -2598,7 +2596,7 @@ static int atmel_serial_probe(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, port); - if (port->uart.rs485.flags & SER_RS485_ENABLED) { + if (rs485_enabled) { UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL); UART_PUT_CR(&port->uart, ATMEL_US_RTSEN); } diff --git a/drivers/tty/serial/mcf.c b/drivers/tty/serial/mcf.c index d7be1f18545b..fdd5c7bd1e8d 100644 --- a/drivers/tty/serial/mcf.c +++ b/drivers/tty/serial/mcf.c @@ -257,12 +257,12 @@ static void mcf_set_termios(struct uart_port *port, struct ktermios *termios, mr2 |= MCFUART_MR2_TXCTS; } + spin_lock_irqsave(&port->lock, flags); if (port->rs485.flags & SER_RS485_ENABLED) { dev_dbg(port->dev, "Setting UART to RS485\n"); mr2 |= MCFUART_MR2_TXRTS; } - spin_lock_irqsave(&port->lock, flags); uart_update_timeout(port, termios->c_cflag, baud); writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR); writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR); @@ -442,10 +442,8 @@ static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser) static int mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485) { struct mcf_uart *pp = container_of(port, struct mcf_uart, port); - unsigned long flags; unsigned char mr1, mr2; - spin_lock_irqsave(&port->lock, flags); /* Get mode registers */ mr1 = readb(port->membase + MCFUART_UMR); mr2 = readb(port->membase + MCFUART_UMR); @@ -460,7 +458,6 @@ static int mcf_config_rs485(struct uart_port *port, struct serial_rs485 *rs485) writeb(mr1, port->membase + MCFUART_UMR); writeb(mr2, port->membase + MCFUART_UMR); port->rs485 = *rs485; - spin_unlock_irqrestore(&port->lock, flags); return 0; } diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 050d1b5c7b36..e0bec06a5f60 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1360,12 +1360,10 @@ static int serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) { struct uart_omap_port *up = to_uart_omap_port(port); - unsigned long flags; unsigned int mode; int val; pm_runtime_get_sync(up->dev); - spin_lock_irqsave(&up->port.lock, flags); /* Disable interrupts from this port */ mode = up->ier; @@ -1401,7 +1399,6 @@ serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) serial_out(up, UART_OMAP_SCR, up->scr); } - spin_unlock_irqrestore(&up->port.lock, flags); pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 99fcdba0e3e9..5c8b8f50f787 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1155,8 +1155,16 @@ static int uart_get_icount(struct tty_struct *tty, static int uart_get_rs485_config(struct uart_port *port, struct serial_rs485 __user *rs485) { - if (copy_to_user(rs485, &port->rs485, sizeof(port->rs485))) + unsigned long flags; + struct serial_rs485 aux; + + spin_lock_irqsave(&port->lock, flags); + aux = port->rs485; + spin_unlock_irqrestore(&port->lock, flags); + + if (copy_to_user(rs485, &aux, sizeof(aux))) return -EFAULT; + return 0; } @@ -1165,6 +1173,7 @@ static int uart_set_rs485_config(struct uart_port *port, { struct serial_rs485 rs485; int ret; + unsigned long flags; if (!port->rs485_config) return -ENOIOCTLCMD; @@ -1172,7 +1181,9 @@ static int uart_set_rs485_config(struct uart_port *port, if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) return -EFAULT; + spin_lock_irqsave(&port->lock, flags); ret = port->rs485_config(port, &rs485); + spin_unlock_irqrestore(&port->lock, flags); if (ret) return ret; -- 2.34.1