Merge tag 'tty-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the big tty/serial driver update for 4.14-rc1.

  Well, not all that big, just a number of small serial driver fixes,
  and a new serial driver. Also in here are some much needed goldfish
  tty driver (emulator) fixes to try to get that codebase under control.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (94 commits)
  tty: goldfish: Implement support for kernel 'earlycon' parameter
  tty: goldfish: Use streaming DMA for r/w operations on Ranchu platforms
  tty: goldfish: Refactor constants to better reflect their nature
  serial: 8250_port: Remove useless NULL checks
  earlycon: initialise baud field of earlycon device structure
  tty: hvcs: make ktermios const
  pty: show associative slave of ptmx in fdinfo
  tty: n_gsm: Add compat_ioctl
  tty: hvcs: constify vio_device_id
  tty: hvc_vio: constify vio_device_id
  tty: mips_ejtag_fdc: constify mips_cdmm_device_id
  Introduce 8250_men_mcb
  mcb: introduce mcb_get_resource()
  serial: imx: Avoid post-PIO cleanup if TX DMA is started
  tty: serial: imx: disable irq after suspend
  serial: 8250_uniphier: add suspend/resume support
  serial: 8250_uniphier: use CHAR register for canary to detect power-off
  serial: 8250_uniphier: fix serial port index in private data
  serial: 8250: of: Add new port type for MediaTek BTIF controller on MT7622/23 SoC
  dt-bindings: serial: 8250: Add MediaTek BTIF controller bindings
  ...

45 files changed, 1304 insertions, 213 deletions

diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c
index 9b208bd686e6..804632b4a929 100644
--- a/drivers/tty/serial/21285.c
+++ b/drivers/tty/serial/21285.c
@@ -334,7 +334,7 @@ static int serial21285_verify_port(struct uart_port *port, struct serial_struct
 	return ret;
 }
 
-static struct uart_ops serial21285_ops = {
+static const struct uart_ops serial21285_ops = {
 	.tx_empty	= serial21285_tx_empty,
 	.get_mctrl	= serial21285_get_mctrl,
 	.set_mctrl	= serial21285_set_mctrl,
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index 822be4906763..33a801353114 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -223,12 +223,13 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 		if (IS_ERR(vuart->clk)) {
 			dev_warn(&pdev->dev,
 				"clk or clock-frequency not defined\n");
-			return PTR_ERR(vuart->clk);
+			rc = PTR_ERR(vuart->clk);
+			goto err_sysfs_remove;
 		}
 
 		rc = clk_prepare_enable(vuart->clk);
 		if (rc < 0)
-			return rc;
+			goto err_sysfs_remove;
 
 		clk = clk_get_rate(vuart->clk);
 	}
@@ -286,6 +287,8 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 err_clk_disable:
 	clk_disable_unprepare(vuart->clk);
 	irq_dispose_mapping(port.port.irq);
+err_sysfs_remove:
+	sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
 	return rc;
 }
 
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 1aab3010fbfa..d29b512a7d9f 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -497,6 +497,11 @@ static void univ8250_rsa_support(struct uart_ops *ops)
 #define univ8250_rsa_support(x)		do { } while (0)
 #endif /* CONFIG_SERIAL_8250_RSA */
 
+static inline void serial8250_apply_quirks(struct uart_8250_port *up)
+{
+	up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0;
+}
+
 static void __init serial8250_isa_init_ports(void)
 {
 	struct uart_8250_port *up;
@@ -577,9 +582,7 @@ serial8250_register_ports(struct uart_driver *drv, struct device *dev)
 
 		up->port.dev = dev;
 
-		if (skip_txen_test)
-			up->port.flags |= UPF_NO_TXEN_TEST;
-
+		serial8250_apply_quirks(up);
 		uart_add_one_port(drv, &up->port);
 	}
 }
@@ -1006,9 +1009,6 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		if (up->port.dev)
 			uart->port.dev = up->port.dev;
 
-		if (skip_txen_test)
-			uart->port.flags |= UPF_NO_TXEN_TEST;
-
 		if (up->port.flags & UPF_FIXED_TYPE)
 			uart->port.type = up->port.type;
 
@@ -1048,6 +1048,7 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 				serial8250_isa_config(0, &uart->port,
 						&uart->capabilities);
 
+			serial8250_apply_quirks(uart);
 			ret = uart_add_one_port(&serial8250_reg,
 						&uart->port);
 			if (ret == 0)
@@ -1092,11 +1093,10 @@ void serial8250_unregister_port(int line)
 	uart_remove_one_port(&serial8250_reg, &uart->port);
 	if (serial8250_isa_devs) {
 		uart->port.flags &= ~UPF_BOOT_AUTOCONF;
-		if (skip_txen_test)
-			uart->port.flags |= UPF_NO_TXEN_TEST;
 		uart->port.type = PORT_UNKNOWN;
 		uart->port.dev = &serial8250_isa_devs->dev;
 		uart->capabilities = 0;
+		serial8250_apply_quirks(uart);
 		uart_add_one_port(&serial8250_reg, &uart->port);
 	} else {
 		uart->port.dev = NULL;
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 787b1160d3a5..7e638997bfc2 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -529,7 +529,7 @@ static int dw8250_probe(struct platform_device *pdev)
 		}
 	}
 
-	data->rst = devm_reset_control_get_optional(dev, NULL);
+	data->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
 	if (IS_ERR(data->rst)) {
 		err = PTR_ERR(data->rst);
 		goto err_pclk;
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index 82fc48eca1df..af72ec32e404 100644
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -37,7 +37,7 @@
 #include <asm/io.h>
 #include <asm/serial.h>
 
-static unsigned int __init serial8250_early_in(struct uart_port *port, int offset)
+static unsigned int serial8250_early_in(struct uart_port *port, int offset)
 {
 	int reg_offset = offset;
 	offset <<= port->regshift;
@@ -60,7 +60,7 @@ static unsigned int __init serial8250_early_in(struct uart_port *port, int offse
 	}
 }
 
-static void __init serial8250_early_out(struct uart_port *port, int offset, int value)
+static void serial8250_early_out(struct uart_port *port, int offset, int value)
 {
 	int reg_offset = offset;
 	offset <<= port->regshift;
@@ -89,7 +89,7 @@ static void __init serial8250_early_out(struct uart_port *port, int offset, int
 
 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
 
-static void __init serial_putc(struct uart_port *port, int c)
+static void serial_putc(struct uart_port *port, int c)
 {
 	unsigned int status;
 
@@ -103,7 +103,7 @@ static void __init serial_putc(struct uart_port *port, int c)
 	}
 }
 
-static void __init early_serial8250_write(struct console *console,
+static void early_serial8250_write(struct console *console,
 					const char *s, unsigned int count)
 {
 	struct earlycon_device *device = console->data;
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index c6360fbdf808..c55624703fdf 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -601,7 +601,7 @@ static const struct exar8250_board pbn_exar_XR17V8358 = {
 		(kernel_ulong_t)&bd			\
 	}
 
-static struct pci_device_id exar_pci_tbl[] = {
+static const struct pci_device_id exar_pci_tbl[] = {
 	CONNECT_DEVICE(XR17C152, UART_2_232, pbn_connect),
 	CONNECT_DEVICE(XR17C154, UART_4_232, pbn_connect),
 	CONNECT_DEVICE(XR17C158, UART_8_232, pbn_connect),
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index 4d9dc10e265c..464389b28900 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -50,17 +50,17 @@ static const struct of_device_id of_match[];
 
 static struct earlycon_device *early_device;
 
-static uint8_t __init early_in(struct uart_port *port, int offset)
+static uint8_t early_in(struct uart_port *port, int offset)
 {
 	return readl(port->membase + (offset << 2));
 }
 
-static void __init early_out(struct uart_port *port, int offset, uint8_t value)
+static void early_out(struct uart_port *port, int offset, uint8_t value)
 {
 	writel(value, port->membase + (offset << 2));
 }
 
-static void __init ingenic_early_console_putc(struct uart_port *port, int c)
+static void ingenic_early_console_putc(struct uart_port *port, int c)
 {
 	uint8_t lsr;
 
@@ -71,7 +71,7 @@ static void __init ingenic_early_console_putc(struct uart_port *port, int c)
 	early_out(port, UART_TX, c);
 }
 
-static void __init ingenic_early_console_write(struct console *console,
+static void ingenic_early_console_write(struct console *console,
 					      const char *s, unsigned int count)
 {
 	uart_console_write(&early_device->port, s, count,
diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
new file mode 100644
index 000000000000..308977807994
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -0,0 +1,118 @@
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mcb.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/serial_8250.h>
+#include <uapi/linux/serial_core.h>
+
+struct serial_8250_men_mcb_data {
+	struct uart_8250_port uart;
+	int line;
+};
+
+/*
+ * The Z125 16550-compatible UART has no fixed base clock assigned
+ * So, depending on the board we're on, we need to adjust the
+ * parameter in order to really set the correct baudrate, and
+ * do so if possible without user interaction
+ */
+static u32 men_z125_lookup_uartclk(struct mcb_device *mdev)
+{
+	/* use default value if board is not available below */
+	u32 clkval = 1041666;
+
+	dev_info(&mdev->dev, "%s on board %s\n",
+		dev_name(&mdev->dev),
+		mdev->bus->name);
+	if  (strncmp(mdev->bus->name, "F075", 4) == 0)
+		clkval = 1041666;
+	else if  (strncmp(mdev->bus->name, "F216", 4) == 0)
+		clkval = 1843200;
+	else if (strncmp(mdev->bus->name, "G215", 4) == 0)
+		clkval = 1843200;
+	else
+		dev_info(&mdev->dev,
+			 "board not detected, using default uartclk\n");
+
+	clkval = clkval  << 4;
+
+	return clkval;
+}
+
+static int serial_8250_men_mcb_probe(struct mcb_device *mdev,
+				     const struct mcb_device_id *id)
+{
+	struct serial_8250_men_mcb_data *data;
+	struct resource *mem;
+
+	data = devm_kzalloc(&mdev->dev,
+			    sizeof(struct serial_8250_men_mcb_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	mcb_set_drvdata(mdev, data);
+	data->uart.port.dev = mdev->dma_dev;
+	spin_lock_init(&data->uart.port.lock);
+
+	data->uart.port.type = PORT_16550;
+	data->uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
+	data->uart.port.iotype = UPIO_MEM;
+	data->uart.port.uartclk = men_z125_lookup_uartclk(mdev);
+	data->uart.port.regshift = 0;
+	data->uart.port.fifosize = 60;
+
+	mem = mcb_get_resource(mdev, IORESOURCE_MEM);
+	if (mem == NULL)
+		return -ENXIO;
+
+	data->uart.port.irq = mcb_get_irq(mdev);
+
+	data->uart.port.membase = devm_ioremap_resource(&mdev->dev, mem);
+	if (IS_ERR(data->uart.port.membase))
+		return PTR_ERR_OR_ZERO(data->uart.port.membase);
+
+	data->uart.port.mapbase = (unsigned long) mem->start;
+	data->uart.port.iobase = data->uart.port.mapbase;
+
+	/* ok, register the port */
+	data->line = serial8250_register_8250_port(&data->uart);
+	if (data->line < 0)
+		return data->line;
+
+	dev_info(&mdev->dev, "found 16Z125 UART: ttyS%d\n", data->line);
+
+	return 0;
+}
+
+static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
+{
+	struct serial_8250_men_mcb_data *data = mcb_get_drvdata(mdev);
+
+	if (data)
+		serial8250_unregister_port(data->line);
+}
+
+static const struct mcb_device_id serial_8250_men_mcb_ids[] = {
+	{ .device = 0x7d },
+	{ }
+};
+MODULE_DEVICE_TABLE(mcb, serial_8250_men_mcb_ids);
+
+static struct mcb_driver mcb_driver = {
+	.driver = {
+		.name = "8250_men_mcb",
+		.owner = THIS_MODULE,
+	},
+	.probe = serial_8250_men_mcb_probe,
+	.remove = serial_8250_men_mcb_remove,
+	.id_table = serial_8250_men_mcb_ids,
+};
+module_mcb_driver(mcb_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("MEN 16z125 8250 UART driver");
+MODULE_AUTHOR("Michael Moese <michael.moese@men.de");
+MODULE_ALIAS("mcb:16z125");
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index ce0cc471bfc3..fb45770d47aa 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -171,10 +171,7 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 	}
 
 	data->bus_clk = devm_clk_get(&pdev->dev, "bus");
-	if (IS_ERR(data->bus_clk))
-		return PTR_ERR(data->bus_clk);
-
-	return 0;
+	return PTR_ERR_OR_ZERO(data->bus_clk);
 }
 
 static int mtk8250_probe(struct platform_device *pdev)
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 0cf95fddccfc..1222c005fb98 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -18,6 +18,7 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
 #include <linux/clk.h>
 #include <linux/reset.h>
 
@@ -65,6 +66,10 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 	int ret;
 
 	memset(port, 0, sizeof *port);
+
+	pm_runtime_enable(&ofdev->dev);
+	pm_runtime_get_sync(&ofdev->dev);
+
 	if (of_property_read_u32(np, "clock-frequency", &clk)) {
 
 		/* Get clk rate through clk driver if present */
@@ -72,12 +77,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 		if (IS_ERR(info->clk)) {
 			dev_warn(&ofdev->dev,
 				"clk or clock-frequency not defined\n");
-			return PTR_ERR(info->clk);
+			ret = PTR_ERR(info->clk);
+			goto err_pmruntime;
 		}
 
 		ret = clk_prepare_enable(info->clk);
 		if (ret < 0)
-			return ret;
+			goto err_pmruntime;
 
 		clk = clk_get_rate(info->clk);
 	}
@@ -88,7 +94,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 	ret = of_address_to_resource(np, 0, &resource);
 	if (ret) {
 		dev_warn(&ofdev->dev, "invalid address\n");
-		goto out;
+		goto err_unprepare;
 	}
 
 	spin_lock_init(&port->lock);
@@ -130,23 +136,23 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 			dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
 				 prop);
 			ret = -EINVAL;
-			goto out;
+			goto err_dispose;
 		}
 	}
 
 	info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
 	if (IS_ERR(info->rst))
-		goto out;
+		goto err_dispose;
 	ret = reset_control_deassert(info->rst);
 	if (ret)
-		goto out;
+		goto err_dispose;
 
 	port->type = type;
 	port->uartclk = clk;
 	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
 		| UPF_FIXED_PORT | UPF_FIXED_TYPE;
 
-	if (of_find_property(np, "no-loopback-test", NULL))
+	if (of_property_read_bool(np, "no-loopback-test"))
 		port->flags |= UPF_SKIP_TEST;
 
 	port->dev = &ofdev->dev;
@@ -167,9 +173,13 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 		port->handle_irq = fsl8250_handle_irq;
 
 	return 0;
-out:
-	if (info->clk)
-		clk_disable_unprepare(info->clk);
+err_dispose:
+	irq_dispose_mapping(port->irq);
+err_unprepare:
+	clk_disable_unprepare(info->clk);
+err_pmruntime:
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
 	return ret;
 }
 
@@ -190,7 +200,7 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 	if (!match)
 		return -EINVAL;
 
-	if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
+	if (of_property_read_bool(ofdev->dev.of_node, "used-by-rtas"))
 		return -EBUSY;
 
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
@@ -201,7 +211,7 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 	memset(&port8250, 0, sizeof(port8250));
 	ret = of_platform_serial_setup(ofdev, port_type, &port8250.port, info);
 	if (ret)
-		goto out;
+		goto err_free;
 
 	if (port8250.port.fifosize)
 		port8250.capabilities = UART_CAP_FIFO;
@@ -217,15 +227,19 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 
 	ret = serial8250_register_8250_port(&port8250);
 	if (ret < 0)
-		goto out;
+		goto err_dispose;
 
 	info->type = port_type;
 	info->line = ret;
 	platform_set_drvdata(ofdev, info);
 	return 0;
-out:
-	kfree(info);
+err_dispose:
 	irq_dispose_mapping(port8250.port.irq);
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
+	clk_disable_unprepare(info->clk);
+err_free:
+	kfree(info);
 	return ret;
 }
 
@@ -239,8 +253,9 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
 	serial8250_unregister_port(info->line);
 
 	reset_control_assert(info->rst);
-	if (info->clk)
-		clk_disable_unprepare(info->clk);
+	pm_runtime_put_sync(&ofdev->dev);
+	pm_runtime_disable(&ofdev->dev);
+	clk_disable_unprepare(info->clk);
 	kfree(info);
 	return 0;
 }
@@ -254,9 +269,10 @@ static int of_serial_suspend(struct device *dev)
 
 	serial8250_suspend_port(info->line);
 
-	if (info->clk && (!uart_console(port) || console_suspend_enabled))
+	if (!uart_console(port) || console_suspend_enabled) {
+		pm_runtime_put_sync(dev);
 		clk_disable_unprepare(info->clk);
-
+	}
 	return 0;
 }
 
@@ -266,8 +282,10 @@ static int of_serial_resume(struct device *dev)
 	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
 	struct uart_port *port = &port8250->port;
 
-	if (info->clk && (!uart_console(port) || console_suspend_enabled))
+	if (!uart_console(port) || console_suspend_enabled) {
+		pm_runtime_get_sync(dev);
 		clk_prepare_enable(info->clk);
+	}
 
 	serial8250_resume_port(info->line);
 
@@ -295,6 +313,8 @@ static const struct of_device_id of_platform_serial_table[] = {
 		.data = (void *)PORT_ALTR_16550_F64, },
 	{ .compatible = "altr,16550-FIFO128",
 		.data = (void *)PORT_ALTR_16550_F128, },
+	{ .compatible = "mediatek,mtk-btif",
+		.data = (void *)PORT_MTK_BTIF, },
 	{ .compatible = "mrvl,mmp-uart",
 		.data = (void *)PORT_XSCALE, },
 	{ .compatible = "ti,da830-uart", .data = (void *)PORT_DA830, },
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 00e51a064388..0c101a7470b0 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1548,7 +1548,7 @@ static int skip_tx_en_setup(struct serial_private *priv,
 			const struct pciserial_board *board,
 			struct uart_8250_port *port, int idx)
 {
-	port->port.flags |= UPF_NO_TXEN_TEST;
+	port->port.quirks |= UPQ_NO_TXEN_TEST;
 	dev_dbg(&priv->dev->dev,
 		"serial8250: skipping TxEn test for device [%04x:%04x] subsystem [%04x:%04x]\n",
 		priv->dev->vendor, priv->dev->device,
@@ -3384,17 +3384,8 @@ static const struct pci_device_id blacklist[] = {
 	{ PCI_VDEVICE(COMMTECH, PCI_ANY_ID), },
 };
 
-/*
- * Given a complete unknown PCI device, try to use some heuristics to
- * guess what the configuration might be, based on the pitiful PCI
- * serial specs.  Returns 0 on success, 1 on failure.
- */
-static int
-serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
+static int serial_pci_is_class_communication(struct pci_dev *dev)
 {
-	const struct pci_device_id *bldev;
-	int num_iomem, num_port, first_port = -1, i;
-
 	/*
 	 * If it is not a communications device or the programming
 	 * interface is greater than 6, give up.
@@ -3407,6 +3398,13 @@ serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
 	    (dev->class & 0xff) > 6)
 		return -ENODEV;
 
+	return 0;
+}
+
+static int serial_pci_is_blacklisted(struct pci_dev *dev)
+{
+	const struct pci_device_id *bldev;
+
 	/*
 	 * Do not access blacklisted devices that are known not to
 	 * feature serial ports or are handled by other modules.
@@ -3419,6 +3417,19 @@ serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
 			return -ENODEV;
 	}
 
+	return 0;
+}
+
+/*
+ * Given a complete unknown PCI device, try to use some heuristics to
+ * guess what the configuration might be, based on the pitiful PCI
+ * serial specs.  Returns 0 on success, -ENODEV on failure.
+ */
+static int
+serial_pci_guess_board(struct pci_dev *dev, struct pciserial_board *board)
+{
+	int num_iomem, num_port, first_port = -1, i;
+
 	num_iomem = num_port = 0;
 	for (i = 0; i < PCI_NUM_BAR_RESOURCES; i++) {
 		if (pci_resource_flags(dev, i) & IORESOURCE_IO) {
@@ -3639,6 +3650,14 @@ pciserial_init_one(struct pci_dev *dev, const struct pci_device_id *ent)
 
 	board = &pci_boards[ent->driver_data];
 
+	rc = serial_pci_is_class_communication(dev);
+	if (rc)
+		return rc;
+
+	rc = serial_pci_is_blacklisted(dev);
+	if (rc)
+		return rc;
+
 	rc = pcim_enable_device(dev);
 	pci_save_state(dev);
 	if (rc)
@@ -3723,7 +3742,7 @@ static int pciserial_resume_one(struct device *dev)
 static SIMPLE_DEV_PM_OPS(pciserial_pm_ops, pciserial_suspend_one,
 			 pciserial_resume_one);
 
-static struct pci_device_id serial_pci_tbl[] = {
+static const struct pci_device_id serial_pci_tbl[] = {
 	/* Advantech use PCI_DEVICE_ID_ADVANTECH_PCI3620 (0x3620) as 'PCI_SUBVENDOR_ID' */
 	{	PCI_VENDOR_ID_ADVANTECH, PCI_DEVICE_ID_ADVANTECH_PCI3620,
 		PCI_DEVICE_ID_ADVANTECH_PCI3620, 0x0001, 0, 0,
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index a5fe0e66c607..f0cc04f62b67 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -37,7 +37,7 @@
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <linux/pm_ru