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 <nicolas.ferre@atmel.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Suggested-by: Alan Cox <alan@linux.intel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ricardo Ribalda Delgado 2014-11-06 09:23:00 +01:00 committed by Greg Kroah-Hartman
parent a9c20a9cf3
commit bd737f8738
4 changed files with 17 additions and 14 deletions

View File

@ -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);
}

View File

@ -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;
}

View File

@ -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);

View File

@ -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;