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Commit a8d70698 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'tty-3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty 

Pull tty/serial fixes from Greg KH:
 "Here are a few tty/serial fixes for 3.15-rc3 that resolve a number of
  reported issues in the 8250 and samsung serial drivers, as well as a
  character loss fix for the tty core that was caused by the lock
  removal patches a release ago"

* tag 'tty-3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial_core: fix uart PORT_UNKNOWN handling
  serial: samsung: Change barrier() to cpu_relax() in console output
  serial: samsung: don't check config for every character
  serial: samsung: Use the passed in "port", fixing kgdb w/ no console
  serial: 8250: Fix thread unsafe __dma_tx_complete function
  8250_core: Fix unwanted TX chars write
  tty: Fix race condition between __tty_buffer_request_room and flush_to_ldisc
parents d0c15ad7 7deb39ed

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

+1 −1
Original line number Diff line number Diff line
@@ -1520,7 +1520,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) 
			status = serial8250_rx_chars(up, status);

	}

	serial8250_modem_status(up);

	if (status & UART_LSR_THRE)

	if (!up->dma && (status & UART_LSR_THRE))

		serial8250_tx_chars(up);



	spin_unlock_irqrestore(&port->lock, flags);

drivers/tty/serial/8250/8250_dma.c

+7 −2
Original line number Diff line number Diff line
@@ -20,12 +20,15 @@ static void __dma_tx_complete(void *param) 
	struct uart_8250_port	*p = param;

	struct uart_8250_dma	*dma = p->dma;

	struct circ_buf		*xmit = &p->port.state->xmit;



	dma->tx_running = 0;

	unsigned long	flags;



	dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,

				UART_XMIT_SIZE, DMA_TO_DEVICE);



	spin_lock_irqsave(&p->port.lock, flags);



	dma->tx_running = 0;



	xmit->tail += dma->tx_size;

	xmit->tail &= UART_XMIT_SIZE - 1;

	p->port.icount.tx += dma->tx_size;
@@ -35,6 +38,8 @@ static void __dma_tx_complete(void *param) 


	if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port))

		serial8250_tx_dma(p);



	spin_unlock_irqrestore(&p->port.lock, flags);

}



static void __dma_rx_complete(void *param)

drivers/tty/serial/samsung.c

+12 −11
Original line number Diff line number Diff line
@@ -1446,8 +1446,8 @@ static int s3c24xx_serial_get_poll_char(struct uart_port *port) 
static void s3c24xx_serial_put_poll_char(struct uart_port *port,

		unsigned char c)

{

	unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);

	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);

	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);

	unsigned int ucon = rd_regl(port, S3C2410_UCON);



	/* not possible to xmit on unconfigured port */

	if (!s3c24xx_port_configured(ucon))
@@ -1455,7 +1455,7 @@ static void s3c24xx_serial_put_poll_char(struct uart_port *port, 


	while (!s3c24xx_serial_console_txrdy(port, ufcon))

		cpu_relax();

	wr_regb(cons_uart, S3C2410_UTXH, c);

	wr_regb(port, S3C2410_UTXH, c);

}



#endif /* CONFIG_CONSOLE_POLL */
@@ -1463,22 +1463,23 @@ static void s3c24xx_serial_put_poll_char(struct uart_port *port, 
static void

s3c24xx_serial_console_putchar(struct uart_port *port, int ch)

{

	unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);

	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);



	/* not possible to xmit on unconfigured port */

	if (!s3c24xx_port_configured(ucon))

		return;

	unsigned int ufcon = rd_regl(port, S3C2410_UFCON);



	while (!s3c24xx_serial_console_txrdy(port, ufcon))

		barrier();

	wr_regb(cons_uart, S3C2410_UTXH, ch);

		cpu_relax();

	wr_regb(port, S3C2410_UTXH, ch);

}



static void

s3c24xx_serial_console_write(struct console *co, const char *s,

			     unsigned int count)

{

	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);



	/* not possible to xmit on unconfigured port */

	if (!s3c24xx_port_configured(ucon))

		return;



	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);

}

drivers/tty/serial/serial_core.c

+21 −18
Original line number Diff line number Diff line
@@ -136,6 +136,11 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, 
	if (uport->type == PORT_UNKNOWN)

		return 1;



	/*

	 * Make sure the device is in D0 state.

	 */

	uart_change_pm(state, UART_PM_STATE_ON);



	/*

	 * Initialise and allocate the transmit and temporary

	 * buffer.
@@ -825,13 +830,15 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, 
		 * If we fail to request resources for the

		 * new port, try to restore the old settings.

		 */

		if (retval && old_type != PORT_UNKNOWN) {

		if (retval) {

			uport->iobase = old_iobase;

			uport->type = old_type;

			uport->hub6 = old_hub6;

			uport->iotype = old_iotype;

			uport->regshift = old_shift;

			uport->mapbase = old_mapbase;



			if (old_type != PORT_UNKNOWN) {

				retval = uport->ops->request_port(uport);

				/*

				 * If we failed to restore the old settings,
@@ -844,6 +851,8 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, 
				 * We failed anyway.

				 */

				retval = -EBUSY;

			}



			/* Added to return the correct error -Ram Gupta */

			goto exit;

		}
@@ -1570,12 +1579,6 @@ static int uart_open(struct tty_struct *tty, struct file *filp) 
		goto err_dec_count;

	}



	/*

	 * Make sure the device is in D0 state.

	 */

	if (port->count == 1)

		uart_change_pm(state, UART_PM_STATE_ON);



	/*

	 * Start up the serial port.

	 */

drivers/tty/tty_buffer.c

+14 −2
Original line number Diff line number Diff line
@@ -255,11 +255,16 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size, 
	if (change || left < size) {

		/* This is the slow path - looking for new buffers to use */

		if ((n = tty_buffer_alloc(port, size)) != NULL) {

			unsigned long iflags;



			n->flags = flags;

			buf->tail = n;



			spin_lock_irqsave(&buf->flush_lock, iflags);

			b->commit = b->used;

			smp_mb();

			b->next = n;

			spin_unlock_irqrestore(&buf->flush_lock, iflags);



		} else if (change)

			size = 0;

		else
@@ -443,6 +448,7 @@ static void flush_to_ldisc(struct work_struct *work) 
	mutex_lock(&buf->lock);



	while (1) {

		unsigned long flags;

		struct tty_buffer *head = buf->head;

		int count;
@@ -450,14 +456,19 @@ static void flush_to_ldisc(struct work_struct *work) 
		if (atomic_read(&buf->priority))

			break;



		spin_lock_irqsave(&buf->flush_lock, flags);

		count = head->commit - head->read;

		if (!count) {

			if (head->next == NULL)

			if (head->next == NULL) {

				spin_unlock_irqrestore(&buf->flush_lock, flags);

				break;

			}

			buf->head = head->next;

			spin_unlock_irqrestore(&buf->flush_lock, flags);

			tty_buffer_free(port, head);

			continue;

		}

		spin_unlock_irqrestore(&buf->flush_lock, flags);



		count = receive_buf(tty, head, count);

		if (!count)
@@ -512,6 +523,7 @@ void tty_buffer_init(struct tty_port *port) 
	struct tty_bufhead *buf = &port->buf;



	mutex_init(&buf->lock);

	spin_lock_init(&buf->flush_lock);

	tty_buffer_reset(&buf->sentinel, 0);

	buf->head = &buf->sentinel;

	buf->tail = &buf->sentinel;