6 files changed, 70 insertions, 16 deletions

diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index 2350fb3bb5e4..c2cecc6f47db 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -487,7 +487,7 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 	port.port.irq = irq_of_parse_and_map(np, 0);
 	port.port.handle_irq = aspeed_vuart_handle_irq;
 	port.port.iotype = UPIO_MEM;
-	port.port.type = PORT_16550A;
+	port.port.type = PORT_ASPEED_VUART;
 	port.port.uartclk = clk;
 	port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
 		| UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST;
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 890fa7ddaa7f..b3c3f7e5851a 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -64,10 +64,19 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 	struct uart_8250_dma		*dma = p->dma;
 	struct circ_buf			*xmit = &p->port.state->xmit;
 	struct dma_async_tx_descriptor	*desc;
+	struct uart_port		*up = &p->port;
 	int ret;
 
-	if (dma->tx_running)
+	if (dma->tx_running) {
+		if (up->x_char) {
+			dmaengine_pause(dma->txchan);
+			uart_xchar_out(up, UART_TX);
+			dmaengine_resume(dma->txchan);
+		}
 		return 0;
+	} else if (up->x_char) {
+		uart_xchar_out(up, UART_TX);
+	}
 
 	if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) {
 		/* We have been called from __dma_tx_complete() */
diff --git a/drivers/tty/serial/8250/8250_gsc.c b/drivers/tty/serial/8250/8250_gsc.c
index 673cda3d011d..948d0a1c6ae8 100644
--- a/drivers/tty/serial/8250/8250_gsc.c
+++ b/drivers/tty/serial/8250/8250_gsc.c
@@ -26,7 +26,7 @@ static int __init serial_init_chip(struct parisc_device *dev)
 	unsigned long address;
 	int err;
 
-#ifdef CONFIG_64BIT
+#if defined(CONFIG_64BIT) && defined(CONFIG_IOSAPIC)
 	if (!dev->irq && (dev->id.sversion == 0xad))
 		dev->irq = iosapic_serial_irq(dev);
 #endif
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index 848d81e3838c..49ae73f4d3a0 100644
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -121,8 +121,7 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 {
 	struct dw_dma_slave *param = &lpss->dma_param;
 	struct pci_dev *pdev = to_pci_dev(port->dev);
-	unsigned int dma_devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
-	struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn);
+	struct pci_dev *dma_dev;
 
 	switch (pdev->device) {
 	case PCI_DEVICE_ID_INTEL_BYT_UART1:
@@ -141,6 +140,8 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 		return -EINVAL;
 	}
 
+	dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
+
 	param->dma_dev = &dma_dev->dev;
 	param->m_master = 0;
 	param->p_master = 1;
@@ -156,6 +157,14 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	return 0;
 }
 
+static void byt_serial_exit(struct lpss8250 *lpss)
+{
+	struct dw_dma_slave *param = &lpss->dma_param;
+
+	/* Paired with pci_get_slot() in the byt_serial_setup() above */
+	put_device(param->dma_dev);
+}
+
 static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 {
 	struct uart_8250_dma *dma = &lpss->data.dma;
@@ -171,6 +180,13 @@ static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	return 0;
 }
 
+static void ehl_serial_exit(struct lpss8250 *lpss)
+{
+	struct uart_8250_port *up = serial8250_get_port(lpss->data.line);
+
+	up->dma = NULL;
+}
+
 #ifdef CONFIG_SERIAL_8250_DMA
 static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
 	.nr_channels = 2,
@@ -345,8 +361,7 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	return 0;
 
 err_exit:
-	if (lpss->board->exit)
-		lpss->board->exit(lpss);
+	lpss->board->exit(lpss);
 	pci_free_irq_vectors(pdev);
 	return ret;
 }
@@ -357,8 +372,7 @@ static void lpss8250_remove(struct pci_dev *pdev)
 
 	serial8250_unregister_port(lpss->data.line);
 
-	if (lpss->board->exit)
-		lpss->board->exit(lpss);
+	lpss->board->exit(lpss);
 	pci_free_irq_vectors(pdev);
 }
 
@@ -366,12 +380,14 @@ static const struct lpss8250_board byt_board = {
 	.freq = 100000000,
 	.base_baud = 2764800,
 	.setup = byt_serial_setup,
+	.exit = byt_serial_exit,
 };
 
 static const struct lpss8250_board ehl_board = {
 	.freq = 200000000,
 	.base_baud = 12500000,
 	.setup = ehl_serial_setup,
+	.exit = ehl_serial_exit,
 };
 
 static const struct lpss8250_board qrk_board = {
diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c
index efa0515139f8..e6c1791609dd 100644
--- a/drivers/tty/serial/8250/8250_mid.c
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -73,6 +73,11 @@ static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
 	return 0;
 }
 
+static void pnw_exit(struct mid8250 *mid)
+{
+	pci_dev_put(mid->dma_dev);
+}
+
 static int tng_handle_irq(struct uart_port *p)
 {
 	struct mid8250 *mid = p->private_data;
@@ -124,6 +129,11 @@ static int tng_setup(struct mid8250 *mid, struct uart_port *p)
 	return 0;
 }
 
+static void tng_exit(struct mid8250 *mid)
+{
+	pci_dev_put(mid->dma_dev);
+}
+
 static int dnv_handle_irq(struct uart_port *p)
 {
 	struct mid8250 *mid = p->private_data;
@@ -330,9 +340,9 @@ static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	pci_set_drvdata(pdev, mid);
 	return 0;
+
 err:
-	if (mid->board->exit)
-		mid->board->exit(mid);
+	mid->board->exit(mid);
 	return ret;
 }
 
@@ -342,8 +352,7 @@ static void mid8250_remove(struct pci_dev *pdev)
 
 	serial8250_unregister_port(mid->line);
 
-	if (mid->board->exit)
-		mid->board->exit(mid);
+	mid->board->exit(mid);
 }
 
 static const struct mid8250_board pnw_board = {
@@ -351,6 +360,7 @@ static const struct mid8250_board pnw_board = {
 	.freq = 50000000,
 	.base_baud = 115200,
 	.setup = pnw_setup,
+	.exit = pnw_exit,
 };
 
 static const struct mid8250_board tng_board = {
@@ -358,6 +368,7 @@ static const struct mid8250_board tng_board = {
 	.freq = 38400000,
 	.base_baud = 1843200,
 	.setup = tng_setup,
+	.exit = tng_exit,
 };
 
 static const struct mid8250_board dnv_board = {
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index ec88b706e882..723ec0806799 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -307,6 +307,14 @@ static const struct serial8250_config uart_config[] = {
 		.rxtrig_bytes	= {1, 32, 64, 112},
 		.flags		= UART_CAP_FIFO | UART_CAP_SLEEP,
 	},
+	[PORT_ASPEED_VUART] = {
+		.name		= "ASPEED VUART",
+		.fifo_size	= 16,
+		.tx_loadsz	= 16,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
 };
 
 /* Uart divisor latch read */
@@ -1615,6 +1623,18 @@ static inline void start_tx_rs485(struct uart_port *port)
 	struct uart_8250_port *up = up_to_u8250p(port);
 	struct uart_8250_em485 *em485 = up->em485;
 
+	/*
+	 * While serial8250_em485_handle_stop_tx() is a noop if
+	 * em485->active_timer != &em485->stop_tx_timer, it might happen that
+	 * the timer is still armed and triggers only after the current bunch of
+	 * chars is send and em485->active_timer == &em485->stop_tx_timer again.
+	 * So cancel the timer. There is still a theoretical race condition if
+	 * the timer is already running and only comes around to check for
+	 * em485->active_timer when &em485->stop_tx_timer is armed again.
+	 */
+	if (em485->active_timer == &em485->stop_tx_timer)
+		hrtimer_try_to_cancel(&em485->stop_tx_timer);
+
 	em485->active_timer = NULL;
 
 	if (em485->tx_stopped) {
@@ -1799,9 +1819,7 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 	int count;
 
 	if (port->x_char) {
-		serial_out(up, UART_TX, port->x_char);
-		port->icount.tx++;
-		port->x_char = 0;
+		uart_xchar_out(port, UART_TX);
 		return;
 	}
 	if (uart_tx_stopped(port)) {