Commit 478d1051 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Greg Kroah-Hartman
Browse files

sc16is7xx: use kworker for RS-485 configuration 



RS-485 configuration is also done under the spinlock
so no blocking I/O allowed.

Signed-off-by: default avatarJakub Kicinski <kubakici@wp.pl>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 059d5815

drivers/tty/serial/sc16is7xx.c

+29 −12
Original line number Diff line number Diff line
@@ -303,6 +303,7 @@ struct sc16is7xx_devtype { 


#define SC16IS7XX_RECONF_MD		(1 << 0)

#define SC16IS7XX_RECONF_IER		(1 << 1)

#define SC16IS7XX_RECONF_RS485		(1 << 2)



struct sc16is7xx_one_config {

	unsigned int			flags;
@@ -668,6 +669,26 @@ static void sc16is7xx_tx_proc(struct kthread_work *ws) 
	sc16is7xx_handle_tx(port);

}



static void sc16is7xx_reconf_rs485(struct uart_port *port)

{

	const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |

			 SC16IS7XX_EFCR_RTS_INVERT_BIT;

	u32 efcr = 0;

	struct serial_rs485 *rs485 = &port->rs485;

	unsigned long irqflags;



	spin_lock_irqsave(&port->lock, irqflags);

	if (rs485->flags & SER_RS485_ENABLED) {

		efcr |=	SC16IS7XX_EFCR_AUTO_RS485_BIT;



		if (rs485->flags & SER_RS485_RTS_AFTER_SEND)

			efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;

	}

	spin_unlock_irqrestore(&port->lock, irqflags);



	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);

}



static void sc16is7xx_reg_proc(struct kthread_work *ws)

{

	struct sc16is7xx_one *one = to_sc16is7xx_one(ws, reg_work);
@@ -688,6 +709,9 @@ static void sc16is7xx_reg_proc(struct kthread_work *ws) 
	if (config.flags & SC16IS7XX_RECONF_IER)

		sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG,

				      config.ier_clear, 0);



	if (config.flags & SC16IS7XX_RECONF_RS485)

		sc16is7xx_reconf_rs485(&one->port);

}



static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
@@ -845,9 +869,8 @@ static void sc16is7xx_set_termios(struct uart_port *port, 
static int sc16is7xx_config_rs485(struct uart_port *port,

				  struct serial_rs485 *rs485)

{

	const u32 mask = SC16IS7XX_EFCR_AUTO_RS485_BIT |

			 SC16IS7XX_EFCR_RTS_INVERT_BIT;

	u32 efcr = 0;

	struct sc16is7xx_port *s = dev_get_drvdata(port->dev);

	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);



	if (rs485->flags & SER_RS485_ENABLED) {

		bool rts_during_rx, rts_during_tx;
@@ -855,13 +878,7 @@ static int sc16is7xx_config_rs485(struct uart_port *port, 
		rts_during_rx = rs485->flags & SER_RS485_RTS_AFTER_SEND;

		rts_during_tx = rs485->flags & SER_RS485_RTS_ON_SEND;



		efcr |= SC16IS7XX_EFCR_AUTO_RS485_BIT;



		if (!rts_during_rx && rts_during_tx)

			/* default */;

		else if (rts_during_rx && !rts_during_tx)

			efcr |= SC16IS7XX_EFCR_RTS_INVERT_BIT;

		else

		if (rts_during_rx == rts_during_tx)

			dev_err(port->dev,

				"unsupported RTS signalling on_send:%d after_send:%d - exactly one of RS485 RTS flags should be set\n",

				rts_during_tx, rts_during_rx);
@@ -875,9 +892,9 @@ static int sc16is7xx_config_rs485(struct uart_port *port, 
			return -EINVAL;

	}



	sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, mask, efcr);



	port->rs485 = *rs485;

	one->config.flags |= SC16IS7XX_RECONF_RS485;

	queue_kthread_work(&s->kworker, &one->reg_work);



	return 0;

}