Commit a4416cd1 authored by Peter Hurley's avatar Peter Hurley Committed by Greg Kroah-Hartman
Browse files

serial: 8250: Separate legacy irq handling from core port operations 



Prepare for 8250 split; decouple irq setup/teardown and handler from
core port operations.

Introduce setup_irq() and release_irq() 8250 driver methods; the 8250
core will use these methods to install and remove irq handling for
the given 8250 port.

Refactor irq chain linking/unlinking from 8250 core into
univ8250_setup_irq()/univ8250_release_irq() for the universal 8250 driver.

Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 6e281571

drivers/tty/serial/8250/8250_core.c

+53 −30
Original line number Diff line number Diff line
@@ -1890,6 +1890,48 @@ static void serial8250_backup_timeout(unsigned long data) 
		jiffies + uart_poll_timeout(&up->port) + HZ / 5);

}



static int univ8250_setup_irq(struct uart_8250_port *up)

{

	struct uart_port *port = &up->port;

	int retval = 0;



	/*

	 * The above check will only give an accurate result the first time

	 * the port is opened so this value needs to be preserved.

	 */

	if (up->bugs & UART_BUG_THRE) {

		pr_debug("ttyS%d - using backup timer\n", serial_index(port));



		up->timer.function = serial8250_backup_timeout;

		up->timer.data = (unsigned long)up;

		mod_timer(&up->timer, jiffies +

			  uart_poll_timeout(port) + HZ / 5);

	}



	/*

	 * If the "interrupt" for this port doesn't correspond with any

	 * hardware interrupt, we use a timer-based system.  The original

	 * driver used to do this with IRQ0.

	 */

	if (!port->irq) {

		up->timer.data = (unsigned long)up;

		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));

	} else

		retval = serial_link_irq_chain(up);



	return retval;

}



static void univ8250_release_irq(struct uart_8250_port *up)

{

	struct uart_port *port = &up->port;



	del_timer_sync(&up->timer);

	up->timer.function = serial8250_timeout;

	if (port->irq)

		serial_unlink_irq_chain(up);

}



static unsigned int serial8250_tx_empty(struct uart_port *port)

{

	struct uart_8250_port *up = up_to_u8250p(port);
@@ -2194,35 +2236,12 @@ int serial8250_do_startup(struct uart_port *port) 
		if ((!(iir1 & UART_IIR_NO_INT) && (iir & UART_IIR_NO_INT)) ||

		    up->port.flags & UPF_BUG_THRE) {

			up->bugs |= UART_BUG_THRE;

			pr_debug("ttyS%d - using backup timer\n",

				 serial_index(port));

		}

	}



	/*

	 * The above check will only give an accurate result the first time

	 * the port is opened so this value needs to be preserved.

	 */

	if (up->bugs & UART_BUG_THRE) {

		up->timer.function = serial8250_backup_timeout;

		up->timer.data = (unsigned long)up;

		mod_timer(&up->timer, jiffies +

			uart_poll_timeout(port) + HZ / 5);

	}



	/*

	 * If the "interrupt" for this port doesn't correspond with any

	 * hardware interrupt, we use a timer-based system.  The original

	 * driver used to do this with IRQ0.

	 */

	if (!port->irq) {

		up->timer.data = (unsigned long)up;

		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));

	} else {

		retval = serial_link_irq_chain(up);

	retval = up->ops->setup_irq(up);

	if (retval)

		goto out;

	}



	/*

	 * Now, initialize the UART
@@ -2380,10 +2399,7 @@ void serial8250_do_shutdown(struct uart_port *port) 
	serial_port_in(port, UART_RX);

	serial8250_rpm_put(up);



	del_timer_sync(&up->timer);

	up->timer.function = serial8250_timeout;

	if (port->irq)

		serial_unlink_irq_chain(up);

	up->ops->release_irq(up);

}

EXPORT_SYMBOL_GPL(serial8250_do_shutdown);
@@ -3083,6 +3099,11 @@ static struct uart_ops serial8250_pops = { 
#endif

};



static const struct uart_8250_ops univ8250_driver_ops = {

	.setup_irq	= univ8250_setup_irq,

	.release_irq	= univ8250_release_irq,

};



static struct uart_8250_port serial8250_ports[UART_NR];



/**
@@ -3137,6 +3158,8 @@ static void __init serial8250_isa_init_ports(void) 
		up->timer.function = serial8250_timeout;

		up->cur_iotype = 0xFF;



		up->ops = &univ8250_driver_ops;



		/*

		 * ALPHA_KLUDGE_MCR needs to be killed.

		 */

include/linux/serial_8250.h

+15 −0
Original line number Diff line number Diff line
@@ -60,6 +60,20 @@ enum { 
};



struct uart_8250_dma;

struct uart_8250_port;



/**

 * 8250 core driver operations

 *

 * @setup_irq()		Setup irq handling. The universal 8250 driver links this

 *			port to the irq chain. Other drivers may @request_irq().

 * @release_irq()	Undo irq handling. The universal 8250 driver unlinks

 *			the port from the irq chain.

 */

struct uart_8250_ops {

	int		(*setup_irq)(struct uart_8250_port *);

	void		(*release_irq)(struct uart_8250_port *);

};



/*

 * This should be used by drivers which want to register
@@ -100,6 +114,7 @@ struct uart_8250_port { 
	unsigned char		msr_saved_flags;



	struct uart_8250_dma	*dma;

	const struct uart_8250_ops *ops;



	/* 8250 specific callbacks */

	int			(*dl_read)(struct uart_8250_port *);

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