Merge tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here are the big set of tty and serial driver updates for 5.6-rc1

  Included in here are:
   - dummy_con cleanups (touches lots of arch code)
   - sysrq logic cleanups (touches lots of serial drivers)
   - samsung driver fixes (wasn't really being built)
   - conmakeshash move to tty subdir out of scripts
   - lots of small tty/serial driver updates

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

* tag 'tty-5.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
  tty: n_hdlc: Use flexible-array member and struct_size() helper
  tty: baudrate: SPARC supports few more baud rates
  tty: baudrate: Synchronise baud_table[] and baud_bits[]
  tty: serial: meson_uart: Add support for kernel debugger
  serial: imx: fix a race condition in receive path
  serial: 8250_bcm2835aux: Document struct bcm2835aux_data
  serial: 8250_bcm2835aux: Use generic remapping code
  serial: 8250_bcm2835aux: Allocate uart_8250_port on stack
  serial: 8250_bcm2835aux: Suppress register_port error on -EPROBE_DEFER
  serial: 8250_bcm2835aux: Suppress clk_get error on -EPROBE_DEFER
  serial: 8250_bcm2835aux: Fix line mismatch on driver unbind
  serial_core: Remove unused member in uart_port
  vt: Correct comment documenting do_take_over_console()
  vt: Delete comment referencing non-existent unbind_con_driver()
  arch/xtensa/setup: Drop dummy_con initialization
  arch/x86/setup: Drop dummy_con initialization
  arch/unicore32/setup: Drop dummy_con initialization
  arch/sparc/setup: Drop dummy_con initialization
  arch/sh/setup: Drop dummy_con initialization
  arch/s390/setup: Drop dummy_con initialization
  ...

9 files changed, 49 insertions, 44 deletions

diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index 6e67fd89445a..d657aa14c3e4 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -5,10 +5,6 @@
  *    Copyright (C) 2016 Jeremy Kerr <jk@ozlabs.org>, IBM Corp.
  *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
  */
-#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -406,6 +402,7 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 	port.port.unthrottle = aspeed_vuart_unthrottle;
 	port.port.status = UPSTAT_SYNC_FIFO;
 	port.port.dev = &pdev->dev;
+	port.port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
 
 	rc = sysfs_create_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
 	if (rc < 0)
diff --git a/drivers/tty/serial/8250/8250_bcm2835aux.c b/drivers/tty/serial/8250/8250_bcm2835aux.c
index 8ce700c1a7fc..e70e3cc30050 100644
--- a/drivers/tty/serial/8250/8250_bcm2835aux.c
+++ b/drivers/tty/serial/8250/8250_bcm2835aux.c
@@ -16,14 +16,19 @@
 
 #include "8250.h"
 
+/**
+ * struct bcm2835aux_data - driver private data of BCM2835 auxiliary UART
+ * @clk: clock producer of the port's uartclk
+ * @line: index of the port's serial8250_ports[] entry
+ */
 struct bcm2835aux_data {
-	struct uart_8250_port uart;
 	struct clk *clk;
 	int line;
 };
 
 static int bcm2835aux_serial_probe(struct platform_device *pdev)
 {
+	struct uart_8250_port up = { };
 	struct bcm2835aux_data *data;
 	struct resource *res;
 	int ret;
@@ -34,23 +39,21 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	/* initialize data */
-	spin_lock_init(&data->uart.port.lock);
-	data->uart.capabilities = UART_CAP_FIFO | UART_CAP_MINI;
-	data->uart.port.dev = &pdev->dev;
-	data->uart.port.regshift = 2;
-	data->uart.port.type = PORT_16550;
-	data->uart.port.iotype = UPIO_MEM;
-	data->uart.port.fifosize = 8;
-	data->uart.port.flags = UPF_SHARE_IRQ |
-				UPF_FIXED_PORT |
-				UPF_FIXED_TYPE |
-				UPF_SKIP_TEST;
+	up.capabilities = UART_CAP_FIFO | UART_CAP_MINI;
+	up.port.dev = &pdev->dev;
+	up.port.regshift = 2;
+	up.port.type = PORT_16550;
+	up.port.iotype = UPIO_MEM;
+	up.port.fifosize = 8;
+	up.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE |
+			UPF_SKIP_TEST | UPF_IOREMAP;
 
 	/* get the clock - this also enables the HW */
 	data->clk = devm_clk_get(&pdev->dev, NULL);
 	ret = PTR_ERR_OR_ZERO(data->clk);
 	if (ret) {
-		dev_err(&pdev->dev, "could not get clk: %d\n", ret);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "could not get clk: %d\n", ret);
 		return ret;
 	}
 
@@ -58,7 +61,7 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0)
 		return ret;
-	data->uart.port.irq = ret;
+	up.port.irq = ret;
 
 	/* map the main registers */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -66,15 +69,13 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "memory resource not found");
 		return -EINVAL;
 	}
-	data->uart.port.membase = devm_ioremap_resource(&pdev->dev, res);
-	ret = PTR_ERR_OR_ZERO(data->uart.port.membase);
-	if (ret)
-		return ret;
+	up.port.mapbase = res->start;
+	up.port.mapsize = resource_size(res);
 
 	/* Check for a fixed line number */
 	ret = of_alias_get_id(pdev->dev.of_node, "serial");
 	if (ret >= 0)
-		data->uart.port.line = ret;
+		up.port.line = ret;
 
 	/* enable the clock as a last step */
 	ret = clk_prepare_enable(data->clk);
@@ -89,13 +90,14 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 	 * so we have to multiply the actual clock by 2
 	 * to get identical baudrates.
 	 */
-	data->uart.port.uartclk = clk_get_rate(data->clk) * 2;
+	up.port.uartclk = clk_get_rate(data->clk) * 2;
 
 	/* register the port */
-	ret = serial8250_register_8250_port(&data->uart);
+	ret = serial8250_register_8250_port(&up);
 	if (ret < 0) {
-		dev_err(&pdev->dev, "unable to register 8250 port - %d\n",
-			ret);
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev,
+				"unable to register 8250 port - %d\n", ret);
 		goto dis_clk;
 	}
 	data->line = ret;
@@ -113,7 +115,7 @@ static int bcm2835aux_serial_remove(struct platform_device *pdev)
 {
 	struct bcm2835aux_data *data = platform_get_drvdata(pdev);
 
-	serial8250_unregister_port(data->uart.port.line);
+	serial8250_unregister_port(data->line);
 	clk_disable_unprepare(data->clk);
 
 	return 0;
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index e682390ce0de..0894a22fd702 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -816,6 +816,7 @@ static int serial8250_probe(struct platform_device *dev)
 		uart.port.flags		= p->flags;
 		uart.port.mapbase	= p->mapbase;
 		uart.port.hub6		= p->hub6;
+		uart.port.has_sysrq	= p->has_sysrq;
 		uart.port.private_data	= p->private_data;
 		uart.port.type		= p->type;
 		uart.port.serial_in	= p->serial_in;
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 108cd55f9c4d..91e9b070d36d 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -186,7 +186,7 @@ static int xr17v35x_startup(struct uart_port *port)
 static void exar_shutdown(struct uart_port *port)
 {
 	unsigned char lsr;
-	bool tx_complete = 0;
+	bool tx_complete = false;
 	struct uart_8250_port *up = up_to_u8250p(port);
 	struct circ_buf *xmit = &port->state->xmit;
 	int i = 0;
@@ -194,9 +194,9 @@ static void exar_shutdown(struct uart_port *port)
 	do {
 		lsr = serial_in(up, UART_LSR);
 		if (lsr & (UART_LSR_TEMT | UART_LSR_THRE))
-			tx_complete = 1;
+			tx_complete = true;
 		else
-			tx_complete = 0;
+			tx_complete = false;
 		usleep_range(1000, 1100);
 	} while (!uart_circ_empty(xmit) && !tx_complete && i++ < 1000);
 
diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
index aa0e216d5ead..0d0c80905c58 100644
--- a/drivers/tty/serial/8250/8250_fsl.c
+++ b/drivers/tty/serial/8250/8250_fsl.c
@@ -1,8 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0
-#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/serial_reg.h>
 #include <linux/serial_8250.h>
 
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 92fbf46ce3bd..531ad67395e0 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -222,8 +222,10 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 
 	if (IS_ENABLED(CONFIG_SERIAL_8250_FSL) &&
 	    (of_device_is_compatible(np, "fsl,ns16550") ||
-	     of_device_is_compatible(np, "fsl,16550-FIFO64")))
+	     of_device_is_compatible(np, "fsl,16550-FIFO64"))) {
 		port->handle_irq = fsl8250_handle_irq;
+		port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
+	}
 
 	return 0;
 err_unprepare:
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index e603c66d6cc4..6f343ca08440 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -8,10 +8,6 @@
  *
  */
 
-#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/io.h>
@@ -1192,6 +1188,7 @@ static int omap8250_probe(struct platform_device *pdev)
 	up.port.throttle = omap_8250_throttle;
 	up.port.unthrottle = omap_8250_unthrottle;
 	up.port.rs485_config = omap_8250_rs485_config;
+	up.port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
 
 	ret = of_alias_get_id(np, "serial");
 	if (ret < 0) {
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 9ff5dfad590a..430e3467aff7 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -11,10 +11,6 @@
  *  membase is an 'ioremapped' cookie.
  */
 
-#if defined(CONFIG_SERIAL_8250_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/ioport.h>
@@ -1001,6 +997,9 @@ static void autoconfig_16550a(struct uart_8250_port *up)
 	up->port.type = PORT_16550A;
 	up->capabilities |= UART_CAP_FIFO;
 
+	if (!IS_ENABLED(CONFIG_SERIAL_8250_16550A_VARIANTS))
+		return;
+
 	/*
 	 * Check for presence of the EFR when DLAB is set.
 	 * Only ST16C650V1 UARTs pass this test.
@@ -3055,6 +3054,7 @@ void serial8250_init_port(struct uart_8250_port *up)
 
 	spin_lock_init(&port->lock);
 	port->ops = &serial8250_pops;
+	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_8250_CONSOLE);
 
 	up->cur_iotype = 0xFF;
 }
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index fab3d4f20667..ffd167e886ae 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -60,6 +60,16 @@ config SERIAL_8250_PNP
 	  This builds standard PNP serial support. You may be able to
 	  disable this feature if you only need legacy serial support.
 
+config SERIAL_8250_16550A_VARIANTS
+	bool "Support for variants of the 16550A serial port"
+	depends on SERIAL_8250
+	help
+	  The 8250 driver can probe for many variants of the venerable 16550A
+	  serial port. Doing so takes additional time at boot.
+
+	  On modern systems, especially those using serial only for a simple
+	  console, you can say N here.
+
 config SERIAL_8250_FINTEK
 	bool "Support for Fintek F81216A LPC to 4 UART RS485 API"
 	depends on SERIAL_8250