Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 530646f4 authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
Browse files

sdio_uart: refcount the tty objects 



The tty can go away underneath us, so we must refcount it. Do the naïve
implementation initially. We will worry about startup shortly.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0395b48c

drivers/mmc/card/sdio_uart.c

+42 −17
Original line number Diff line number Diff line
@@ -172,8 +172,13 @@ static void sdio_uart_port_remove(struct sdio_uart_port *port) 
	sdio_claim_host(func);

	port->func = NULL;

	mutex_unlock(&port->func_lock);

	if (port->opened)

		tty_hangup(port->port.tty);

	if (port->opened) {

		struct tty_struct *tty = tty_port_tty_get(&port->port);

		/* tty_hangup is async so is this safe as is ?? */

		if (tty)

			tty_hangup(tty);

		tty_kref_put(tty);

	}

	mutex_unlock(&port->open_lock);

	sdio_release_irq(func);

	sdio_disable_func(func);
@@ -392,7 +397,7 @@ static void sdio_uart_stop_rx(struct sdio_uart_port *port) 
static void sdio_uart_receive_chars(struct sdio_uart_port *port,

				    unsigned int *status)

{

	struct tty_struct *tty = port->port.tty;

	struct tty_struct *tty = tty_port_tty_get(&port->port);

	unsigned int ch, flag;

	int max_count = 256;
@@ -429,6 +434,7 @@ static void sdio_uart_receive_chars(struct sdio_uart_port *port, 
		}



		if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)

			if (tty)

				tty_insert_flip_char(tty, ch, flag);



		/*
@@ -436,18 +442,22 @@ static void sdio_uart_receive_chars(struct sdio_uart_port *port, 
		 * it doesn't affect the current character.

		 */

		if (*status & ~port->ignore_status_mask & UART_LSR_OE)

			if (tty)

				tty_insert_flip_char(tty, 0, TTY_OVERRUN);



		*status = sdio_in(port, UART_LSR);

	} while ((*status & UART_LSR_DR) && (max_count-- > 0));

	if (tty) {

		tty_flip_buffer_push(tty);

		tty_kref_put(tty);

	}

}



static void sdio_uart_transmit_chars(struct sdio_uart_port *port)

{

	struct circ_buf *xmit = &port->xmit;

	int count;

	struct tty_struct *tty = port->port.tty;

	struct tty_struct *tty;



	if (port->x_char) {

		sdio_out(port, UART_TX, port->x_char);
@@ -455,8 +465,12 @@ static void sdio_uart_transmit_chars(struct sdio_uart_port *port) 
		port->x_char = 0;

		return;

	}

	if (circ_empty(xmit) || tty->stopped || tty->hw_stopped) {



	tty = tty_port_tty_get(&port->port);



	if (tty == NULL || circ_empty(xmit) || tty->stopped || tty->hw_stopped) {

		sdio_uart_stop_tx(port);

		tty_kref_put(tty);

		return;

	}
@@ -474,12 +488,13 @@ static void sdio_uart_transmit_chars(struct sdio_uart_port *port) 


	if (circ_empty(xmit))

		sdio_uart_stop_tx(port);

	tty_kref_put(tty);

}



static void sdio_uart_check_modem_status(struct sdio_uart_port *port)

{

	int status;

	struct tty_struct *tty = port->port.tty;

	struct tty_struct *tty;



	status = sdio_in(port, UART_MSR);
@@ -494,7 +509,8 @@ static void sdio_uart_check_modem_status(struct sdio_uart_port *port) 
		port->icount.dcd++;

	if (status & UART_MSR_DCTS) {

		port->icount.cts++;

		if (tty->termios->c_cflag & CRTSCTS) {

		tty = tty_port_tty_get(&port->port);

		if (tty && (tty->termios->c_cflag & CRTSCTS)) {

			int cts = (status & UART_MSR_CTS);

			if (tty->hw_stopped) {

				if (cts) {
@@ -509,6 +525,7 @@ static void sdio_uart_check_modem_status(struct sdio_uart_port *port) 
				}

			}

		}

		tty_kref_put(tty);

	}

}
@@ -548,8 +565,10 @@ static void sdio_uart_irq(struct sdio_func *func) 
static int sdio_uart_startup(struct sdio_uart_port *port)

{

	unsigned long page;

	int ret;

	struct tty_struct *tty = port->port.tty;

	int ret = -ENOMEM;

	struct tty_struct *tty = tty_port_tty_get(&port->port);



	/* FIXME: What if it is NULL ?? */



	/*

	 * Set the TTY IO error marker - we will only clear this
@@ -560,7 +579,7 @@ static int sdio_uart_startup(struct sdio_uart_port *port) 
	/* Initialise and allocate the transmit buffer. */

	page = __get_free_page(GFP_KERNEL);

	if (!page)

		return -ENOMEM;

		goto err0;

	port->xmit.buf = (unsigned char *)page;

	circ_clear(&port->xmit);
@@ -614,6 +633,7 @@ static int sdio_uart_startup(struct sdio_uart_port *port) 
	sdio_uart_irq(port->func);



	sdio_uart_release_func(port);

	tty_kref_put(tty);

	return 0;



err3:
@@ -622,12 +642,15 @@ static int sdio_uart_startup(struct sdio_uart_port *port) 
	sdio_uart_release_func(port);

err1:

	free_page((unsigned long)port->xmit.buf);

err0:

	tty_kref_put(tty);

	return ret;

}



static void sdio_uart_shutdown(struct sdio_uart_port *port)

{

	int ret;

	struct tty_struct *tty;



	ret = sdio_uart_claim_func(port);

	if (ret)
@@ -637,9 +660,11 @@ static void sdio_uart_shutdown(struct sdio_uart_port *port) 


	/* TODO: wait here for TX FIFO to drain */



	tty = tty_port_tty_get(&port->port);

	/* Turn off DTR and RTS early. */

	if (port->port.tty->termios->c_cflag & HUPCL)

	if (tty && (tty->termios->c_cflag & HUPCL))

		sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);

	tty_kref_put(tty);



	/* Disable interrupts from this port */

	sdio_release_irq(port->func);
@@ -688,11 +713,11 @@ static int sdio_uart_open(struct tty_struct *tty, struct file *filp) 


	if (!port->opened) {

		tty->driver_data = port;

		port->port.tty = tty;

		tty_port_tty_set(&port->port, tty);

		ret = sdio_uart_startup(port);

		if (ret) {

			tty->driver_data = NULL;

			port->port.tty = NULL;

			tty_port_tty_set(&port->port, NULL);

			mutex_unlock(&port->open_lock);

			sdio_uart_port_put(port);

			return ret;
@@ -727,7 +752,7 @@ static void sdio_uart_close(struct tty_struct *tty, struct file * filp) 
		tty->closing = 1;

		sdio_uart_shutdown(port);

		tty_ldisc_flush(tty);

		port->port.tty = NULL;

		tty_port_tty_set(&port->port, NULL);

		tty->driver_data = NULL;

		tty->closing = 0;

	}