Merge tag 'tty-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the large set of TTY and Serial driver patches for 5.9-rc1.

  Lots of bugfixes in here, thanks to syzbot fuzzing for serial and vt
  and console code.

  Other highlights include:

   - much needed vt/vc code cleanup from Jiri Slaby

   - 8250 driver fixes and additions

   - various serial driver updates and feature enhancements

   - locking cleanup for serial/console initializations

   - other minor cleanups

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

* tag 'tty-5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (90 commits)
  MAINTAINERS: enlist Greg formally for console stuff
  vgacon: Fix for missing check in scrollback handling
  Revert "serial: 8250: Let serial core initialise spin lock"
  serial: 8250: Let serial core initialise spin lock
  tty: keyboard, do not speculate on func_table index
  serial: stm32: Add RS485 RTS GPIO control
  serial: 8250_dw: Fix common clocks usage race condition
  serial: 8250_dw: Pass the same rate to the clk round and set rate methods
  serial: 8250_dw: Simplify the ref clock rate setting procedure
  serial: 8250: Add 8250 port clock update method
  tty: serial: imx: add imx earlycon driver
  tty: serial: imx: enable imx serial console port as module
  tty/synclink: remove leftover bits of non-PCI card support
  tty: Use the preferred form for passing the size of a structure type
  tty: Fix identation issues in struct serial_struct32
  tty: Avoid the use of one-element arrays
  serial: msm_serial: add sparse context annotation
  serial: pmac_zilog: add sparse context annotation
  newport_con: vc_color is now in state
  serial: imx: use hrtimers for rs485 delays
  ...

37 files changed, 1626 insertions, 1408 deletions

diff --git a/drivers/tty/moxa.h b/drivers/tty/moxa.h
index 563d2dce80b3..f0a4381b6861 100644
--- a/drivers/tty/moxa.h
+++ b/drivers/tty/moxa.h
@@ -138,7 +138,7 @@
 #define IntrQuit	0x40	/* received QUIT code             */
 #define IntrEOF 	0x80	/* received EOF code              */
 
-#define IntrRxTrigger 	0x100	/* rx data count reach tigger value */
+#define IntrRxTrigger 	0x100	/* rx data count reach trigger value */
 #define IntrTxTrigger 	0x200	/* tx data count below trigger value */
 
 #define Magic_no	(Config_base + 0)
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index aab3cccc6789..87f450b7c177 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -19,6 +19,8 @@
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/workqueue.h>
+#include <linux/notifier.h>
 #include <linux/slab.h>
 #include <linux/acpi.h>
 #include <linux/clk.h>
@@ -43,6 +45,8 @@ struct dw8250_data {
 	int			msr_mask_off;
 	struct clk		*clk;
 	struct clk		*pclk;
+	struct notifier_block	clk_notifier;
+	struct work_struct	clk_work;
 	struct reset_control	*rst;
 
 	unsigned int		skip_autocfg:1;
@@ -54,6 +58,16 @@ static inline struct dw8250_data *to_dw8250_data(struct dw8250_port_data *data)
 	return container_of(data, struct dw8250_data, data);
 }
 
+static inline struct dw8250_data *clk_to_dw8250_data(struct notifier_block *nb)
+{
+	return container_of(nb, struct dw8250_data, clk_notifier);
+}
+
+static inline struct dw8250_data *work_to_dw8250_data(struct work_struct *work)
+{
+	return container_of(work, struct dw8250_data, clk_work);
+}
+
 static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
 {
 	struct dw8250_data *d = to_dw8250_data(p->private_data);
@@ -260,6 +274,46 @@ static int dw8250_handle_irq(struct uart_port *p)
 	return 0;
 }
 
+static void dw8250_clk_work_cb(struct work_struct *work)
+{
+	struct dw8250_data *d = work_to_dw8250_data(work);
+	struct uart_8250_port *up;
+	unsigned long rate;
+
+	rate = clk_get_rate(d->clk);
+	if (rate <= 0)
+		return;
+
+	up = serial8250_get_port(d->data.line);
+
+	serial8250_update_uartclk(&up->port, rate);
+}
+
+static int dw8250_clk_notifier_cb(struct notifier_block *nb,
+				  unsigned long event, void *data)
+{
+	struct dw8250_data *d = clk_to_dw8250_data(nb);
+
+	/*
+	 * We have no choice but to defer the uartclk update due to two
+	 * deadlocks. First one is caused by a recursive mutex lock which
+	 * happens when clk_set_rate() is called from dw8250_set_termios().
+	 * Second deadlock is more tricky and is caused by an inverted order of
+	 * the clk and tty-port mutexes lock. It happens if clock rate change
+	 * is requested asynchronously while set_termios() is executed between
+	 * tty-port mutex lock and clk_set_rate() function invocation and
+	 * vise-versa. Anyway if we didn't have the reference clock alteration
+	 * in the dw8250_set_termios() method we wouldn't have needed this
+	 * deferred event handling complication.
+	 */
+	if (event == POST_RATE_CHANGE) {
+		queue_work(system_unbound_wq, &d->clk_work);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
 static void
 dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 {
@@ -275,27 +329,27 @@ dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,
 			       struct ktermios *old)
 {
-	unsigned int baud = tty_termios_baud_rate(termios);
+	unsigned long newrate = tty_termios_baud_rate(termios) * 16;
 	struct dw8250_data *d = to_dw8250_data(p->private_data);
 	long rate;
 	int ret;
 
 	clk_disable_unprepare(d->clk);
-	rate = clk_round_rate(d->clk, baud * 16);
-	if (rate < 0)
-		ret = rate;
-	else if (rate == 0)
-		ret = -ENOENT;
-	else
-		ret = clk_set_rate(d->clk, rate);
+	rate = clk_round_rate(d->clk, newrate);
+	if (rate > 0) {
+		/*
+		 * Premilinary set the uartclk to the new clock rate so the
+		 * clock update event handler caused by the clk_set_rate()
+		 * calling wouldn't actually update the UART divisor since
+		 * we about to do this anyway.
+		 */
+		swap(p->uartclk, rate);
+		ret = clk_set_rate(d->clk, newrate);
+		if (ret)
+			swap(p->uartclk, rate);
+	}
 	clk_prepare_enable(d->clk);
 
-	if (ret)
-		goto out;
-
-	p->uartclk = rate;
-
-out:
 	p->status &= ~UPSTAT_AUTOCTS;
 	if (termios->c_cflag & CRTSCTS)
 		p->status |= UPSTAT_AUTOCTS;
@@ -319,6 +373,39 @@ static void dw8250_set_ldisc(struct uart_port *p, struct ktermios *termios)
 	serial8250_do_set_ldisc(p, termios);
 }
 
+static int dw8250_startup(struct uart_port *p)
+{
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+	int ret;
+
+	/*
+	 * Some platforms may provide a reference clock shared between several
+	 * devices. In this case before using the serial port first we have to
+	 * make sure that any clock state change is known to the UART port at
+	 * least post factum.
+	 */
+	if (d->clk) {
+		ret = clk_notifier_register(d->clk, &d->clk_notifier);
+		if (ret)
+			dev_warn(p->dev, "Failed to set the clock notifier\n");
+	}
+
+	return serial8250_do_startup(p);
+}
+
+static void dw8250_shutdown(struct uart_port *p)
+{
+	struct dw8250_data *d = to_dw8250_data(p->private_data);
+
+	serial8250_do_shutdown(p);
+
+	if (d->clk) {
+		clk_notifier_unregister(d->clk, &d->clk_notifier);
+
+		flush_work(&d->clk_work);
+	}
+}
+
 /*
  * dw8250_fallback_dma_filter will prevent the UART from getting just any free
  * channel on platforms that have DMA engines, but don't have any channels
@@ -414,6 +501,8 @@ static int dw8250_probe(struct platform_device *pdev)
 	p->serial_out	= dw8250_serial_out;
 	p->set_ldisc	= dw8250_set_ldisc;
 	p->set_termios	= dw8250_set_termios;
+	p->startup	= dw8250_startup;
+	p->shutdown	= dw8250_shutdown;
 
 	p->membase = devm_ioremap(dev, regs->start, resource_size(regs));
 	if (!p->membase)
@@ -475,6 +564,9 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (IS_ERR(data->clk))
 		return PTR_ERR(data->clk);
 
+	INIT_WORK(&data->clk_work, dw8250_clk_work_cb);
+	data->clk_notifier.notifier_call = dw8250_clk_notifier_cb;
+
 	err = clk_prepare_enable(data->clk);
 	if (err)
 		dev_warn(dev, "could not enable optional baudclk: %d\n", err);
diff --git a/drivers/tty/serial/8250/8250_em.c b/drivers/tty/serial/8250/8250_em.c
index 2a76e22d2ec0..db88dee3a399 100644
--- a/drivers/tty/serial/8250/8250_em.c
+++ b/drivers/tty/serial/8250/8250_em.c
@@ -78,14 +78,18 @@ static void serial8250_em_serial_dl_write(struct uart_8250_port *up, int value)
 
 static int serial8250_em_probe(struct platform_device *pdev)
 {
-	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	struct serial8250_em_priv *priv;
 	struct uart_8250_port up;
-	int ret;
+	struct resource *regs;
+	int irq, ret;
 
-	if (!regs || !irq) {
-		dev_err(&pdev->dev, "missing registers or irq\n");
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "missing registers\n");
 		return -EINVAL;
 	}
 
@@ -101,7 +105,7 @@ static int serial8250_em_probe(struct platform_device *pdev)
 
 	memset(&up, 0, sizeof(up));
 	up.port.mapbase = regs->start;
-	up.port.irq = irq->start;
+	up.port.irq = irq;
 	up.port.type = PORT_UNKNOWN;
 	up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
 	up.port.dev = &pdev->dev;
diff --git a/drivers/tty/serial/8250/8250_ingenic.c b/drivers/tty/serial/8250/8250_ingenic.c
index 424c07c5f629..dde766fa465f 100644
--- a/drivers/tty/serial/8250/8250_ingenic.c
+++ b/drivers/tty/serial/8250/8250_ingenic.c
@@ -207,12 +207,11 @@ static unsigned int ingenic_uart_serial_in(struct uart_port *p, int offset)
 static int ingenic_uart_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port uart = {};
-	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	struct ingenic_uart_data *data;
 	const struct ingenic_uart_config *cdata;
 	const struct of_device_id *match;
-	int err, line;
+	struct resource *regs;
+	int irq, err, line;
 
 	match = of_match_device(of_match, &pdev->dev);
 	if (!match) {
@@ -221,8 +220,13 @@ static int ingenic_uart_probe(struct platform_device *pdev)
 	}
 	cdata = match->data;
 
-	if (!regs || !irq) {
-		dev_err(&pdev->dev, "no registers/irq defined\n");
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "no registers defined\n");
 		return -EINVAL;
 	}
 
@@ -238,7 +242,7 @@ static int ingenic_uart_probe(struct platform_device *pdev)
 	uart.port.regshift = 2;
 	uart.port.serial_out = ingenic_uart_serial_out;
 	uart.port.serial_in = ingenic_uart_serial_in;
-	uart.port.irq = irq->start;
+	uart.port.irq = irq;
 	uart.port.dev = &pdev->dev;
 	uart.port.fifosize = cdata->fifosize;
 	uart.tx_loadsz = cdata->tx_loadsz;
diff --git a/drivers/tty/serial/8250/8250_men_mcb.c b/drivers/tty/serial/8250/8250_men_mcb.c
index e985f344b2dd..737c4c31e8a0 100644
--- a/drivers/tty/serial/8250/8250_men_mcb.c
+++ b/drivers/tty/serial/8250/8250_men_mcb.c
@@ -51,7 +51,7 @@ static u32 men_lookup_uartclk(struct mcb_device *mdev)
 	return clkval;
 }
 
-static unsigned int get_num_ports(struct mcb_device *mdev,
+static int get_num_ports(struct mcb_device *mdev,
 				  void __iomem *membase)
 {
 	switch (mdev->id) {
@@ -140,7 +140,7 @@ static void serial_8250_men_mcb_remove(struct mcb_device *mdev)
 		return;
 
 	num_ports = get_num_ports(mdev, data[0].uart.port.membase);
-	if (num_ports < 0 || num_ports > 4) {
+	if (num_ports <= 0 || num_ports > 4) {
 		dev_err(&mdev->dev, "error retrieving number of ports!\n");
 		return;
 	}
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index 98b8a3e30733..7b0dec14c8b8 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -512,13 +512,17 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
 static int mtk8250_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port uart = {};
-	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	struct mtk8250_data *data;
-	int err;
+	struct resource *regs;
+	int irq, err;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
-	if (!regs || !irq) {
-		dev_err(&pdev->dev, "no registers/irq defined\n");
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "no registers defined\n");
 		return -EINVAL;
 	}
 
@@ -542,7 +546,7 @@ static int mtk8250_probe(struct platform_device *pdev)
 
 	spin_lock_init(&uart.port.lock);
 	uart.port.mapbase = regs->start;
-	uart.port.irq = irq->start;
+	uart.port.irq = irq;
 	uart.port.pm = mtk8250_do_pm;
 	uart.port.type = PORT_16550;
 	uart.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT;
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 16cfb887c5a3..562087df7d33 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -1209,17 +1209,21 @@ MODULE_DEVICE_TABLE(of, omap8250_dt_ids);
 
 static int omap8250_probe(struct platform_device *pdev)
 {
-	struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	struct device_node *np = pdev->dev.of_node;
 	struct omap8250_priv *priv;
 	const struct omap8250_platdata *pdata;
 	struct uart_8250_port up;
-	int ret;
+	struct resource *regs;
 	void __iomem *membase;
+	int irq, ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
-	if (!regs || !irq) {
-		dev_err(&pdev->dev, "missing registers or irq\n");
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "missing registers\n");
 		return -EINVAL;
 	}
 
@@ -1236,7 +1240,7 @@ static int omap8250_probe(struct platform_device *pdev)
 	up.port.dev = &pdev->dev;
 	up.port.mapbase = regs->start;
 	up.port.membase = membase;
-	up.port.irq = irq->start;
+	up.port.irq = irq;
 	/*
 	 * It claims to be 16C750 compatible however it is a little different.
 	 * It has EFR and has no FCR7_64byte bit. The AFE (which it claims to
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 1632f7d25acc..09475695effd 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -16,6 +16,7 @@
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/console.h>
+#include <linux/gpio/consumer.h>
 #include <linux/sysrq.h>
 #include <linux/delay.h>
 #include <linux/platform_device.h>
@@ -2631,6 +2632,46 @@ static unsigned int serial8250_get_baud_rate(struct uart_port *port,
 				  (port->uartclk + tolerance) / 16);
 }
 
+/*
+ * Note in order to avoid the tty port mutex deadlock don't use the next method
+ * within the uart port callbacks. Primarily it's supposed to be utilized to
+ * handle a sudden reference clock rate change.
+ */
+void serial8250_update_uartclk(struct uart_port *port, unsigned int uartclk)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int baud, quot, frac = 0;
+	struct ktermios *termios;
+	unsigned long flags;
+
+	mutex_lock(&port->state->port.mutex);
+
+	if (port->uartclk == uartclk)
+		goto out_lock;
+
+	port->uartclk = uartclk;
+	termios = &port->state->port.tty->termios;
+
+	baud = serial8250_get_baud_rate(port, termios, NULL);
+	quot = serial8250_get_divisor(port, baud, &frac);
+
+	serial8250_rpm_get(up);
+	spin_lock_irqsave(&port->lock, flags);
+
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	serial8250_set_divisor(port, baud, quot, frac);
+	serial_port_out(port, UART_LCR, up->lcr);
+	serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+	serial8250_rpm_put(up);
+
+out_lock:
+	mutex_unlock(&port->state->port.mutex);
+}
+EXPORT_SYMBOL_GPL(serial8250_update_uartclk);
+
 void
 serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 			  struct ktermios *old)
diff --git a/drivers/tty/serial/8250/8250_pxa.c b/drivers/tty/serial/8250/8250_pxa.c
index 11612d174716..33ca98bfa5b3 100644
--- a/drivers/tty/serial/8250/8250_pxa.c
+++ b/drivers/tty/serial/8250/8250_pxa.c
@@ -18,7 +18,6 @@
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/of.h>
-#include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
@@ -93,12 +92,15 @@ static int serial_pxa_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port uart = {};
 	struct pxa8250_data *data;
-	struct resource *mmres, *irqres;
-	int ret;
+	struct resource *mmres;
+	int irq, ret;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
 	mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!mmres || !irqres)
+	if (!mmres)
 		return -ENODEV;
 
 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
@@ -121,7 +123,7 @@ static int serial_pxa_probe(struct platform_device *pdev)
 	uart.port.iotype = UPIO_MEM32;
 	uart.port.mapbase = mmres->start;
 	uart.port.regshift = 2;
-	uart.port.irq = irqres->start;
+	uart.port.irq = irq;
 	uart.port.fifosize = 64;
 	uart.port.flags = UPF_IOREMAP | UPF_SKIP_TEST | UPF_FIXED_TYPE;
 	uart.port.dev = &pdev->dev;
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index d2ae033aea40..603137da4736 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -222,7 +222,7 @@ config SERIAL_8250_MANY_PORTS
 	  Say Y here if you have dumb serial boards other than the four
 	  standard COM 1/2/3/4 ports. This may happen if you have an AST
 	  FourPort, Accent Async, Boca (read the Boca mini-HOWTO, available
-	  from <http://www.tldp.org/docs.html#howto>), or other custom
+	  from <https://www.tldp.org/docs.html#howto>), or other custom
 	  serial port hardware which acts similar to standard serial port
 	  hardware. If you only use the standard COM 1/2/3/4 ports, you can
 	  say N here to save some memory. You can also say Y if you have an
@@ -266,7 +266,7 @@ config SERIAL_8250_BOCA
 	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
 	help
 	  Say Y here if you have a Boca serial board.  Please read the Boca
-	  mini-HOWTO, available from <http://www.tldp.org/docs.html#howto>
+	  mini-HOWTO, available from <https://www.tldp.org/docs.html#howto>
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called 8250_boca.
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 780908d43557..8a0352eb337c 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -502,20 +502,27 @@ config SERIAL_IMX
 	  can enable its onboard serial port by enabling this option.
 
 config SERIAL_IMX_CONSOLE
-	bool "Console on IMX serial port"
-	depends on SERIAL_IMX=y
+	tristate "Console on IMX serial port"
+	depends on SERIAL_IMX
 	select SERIAL_CORE_CONSOLE
-	select SERIAL_EARLYCON if OF
 	help
 	  If you have enabled the serial port on the Freescale IMX
-	  CPU you can make it the console by answering Y to this option.
+	  CPU you can make it the console by answering Y/M to this option.
 
-	  Even if you say Y here, the currently visible virtual console
+	  Even if you say Y/M here, the currently visible virtual console
 	  (/dev/tty0) will still be used as the system console by default, but
 	  you can alter that using a kernel command line option such as
 	  "console=ttymxc0". (Try "man bootparam" or see the documentation of
 	  your bootloader about how to pass options to the kernel at boot time.)
 
+config SERIAL_IMX_EARLYCON
+	bool "Earlycon on IMX serial port"
+	depends on OF
+	select SERIAL_EARLYCON
+	help
+	  If you have enabled the earlycon on the Freescale IMX
+	  CPU you can make it the earlycon by answering Y to this option.
+
 config SERIAL_UARTLITE
 	tristate "Xilinx uartlite serial port support"
 	depends on HAS_IOMEM
diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index c90e503d6b57..d0ca9cf29b62 100644
--- a/drivers/tty/serial/altera_jtaguart.c
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -27,7 +27,7 @@
 
 /*
  * Altera JTAG UART register definitions according to the Altera JTAG UART
- * datasheet: http://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf
+ * datasheet: https://www.altera.com/literature/hb/nios2/n2cpu_nii51009.pdf
  */
 
 #define ALTERA_JTAGUART_SIZE			8
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 8efd7c2a34fe..c010f639298d 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2607,7 +2607,6 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
 	uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE);
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = index;
-	spin_lock_init(&uap->port.lock);
 
 	amba_ports[index] = uap;
 
diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 90298c403042..7ca642249224 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1925,6 +1925,9 @@ static void __lpuart32_serial_setbrg(struct uart_port *port,
 			tmp_sbr++;
 		}
 
+		if (tmp_sbr > UARTBAUD_SBR_MASK)
+			continue;
+
 		if (tmp_diff <= baud_diff) {
 			baud_diff = tmp_diff;
 			osr = tmp_osr;
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 1265e8d86d8a..ce8c472cf385 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -20,6 +20,7 @@
 #include <linux/serial.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/ktime.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/rational.h>
 #include <linux/slab.h>
@@ -188,6 +189,13 @@ struct imx_uart_data {
 	enum imx_uart_type devtype;
 };
 
+enum imx_tx_state {
+	OFF,
+	WAIT_AFTER_RTS,
+	SEND,
+	WAIT_AFTER_SEND,
+};
+
 struct imx_port {
 	struct uart_port	port;
 	struct timer_list	timer;
@@ -224,6 +232,10 @@ struct imx_port {
 	unsigned int		dma_tx_nents;
 	unsigned int            saved_reg[10];
 	bool			context_saved;
+
+	enum imx_tx_state	tx_state;
+	struct hrtimer		trigger_start_tx;
+	struct hrtimer		trigger_stop_tx;
 };
 
 struct imx_port_ucrs {
@@ -361,7 +373,7 @@ static inline int imx_uart_is_imx6q(struct imx_port *sport)
 /*
  * Save and restore functions for UCR1, UCR2 and UCR3 registers
  */
-#if defined(CONFIG_SERIAL_IMX_CONSOLE)
+#if IS_ENABLED(CONFIG_SERIAL_IMX_CONSOLE)
 static void imx_uart_ucrs_save(struct imx_port *sport,
 			       struct imx_port_ucrs *ucr)
 {
@@ -400,6 +412,15 @@ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
 	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 }
 
+static void start_hrtimer_ms(struct hrtimer *hrt, unsigned long msec)
+{
+       long sec = msec / MSEC_PER_SEC;
+       long nsec = (msec % MSEC_PER_SEC) * 1000000;
+       ktime_t t = ktime_set(sec, nsec);
+
+       hrtimer_start(hrt, t, HRTIMER_MODE_REL);
+}
+
 /* called with port.lock taken and irqs off */
 static void imx_uart_start_rx(struct uart_port *port)
 {
@@ -427,7 +448,10 @@ static void imx_uart_start_rx(struct uart_port *port)
 static void imx_uart_stop_tx(struct uart_port *port)
 {
 	struct imx_port *sport = (struct imx_port *)port;
-	u32 ucr1;
+	u32 ucr1, ucr4, usr2;
+
+	if (sport->tx_state == OFF)
+		return;
 
 	/*
 	 * We are maybe in the SMP context, so if the DMA TX thread is running
@@ -439,21 +463,44 @@ static void imx_uart_stop_tx(struct uart_port *port)
 	ucr1 = imx_uart_readl(sport, UCR1);
 	imx_uart_writel(sport, ucr1 & ~UCR1_TRDYEN, UCR1);
 
-	/* in rs485 mode disable transmitter if shifter is empty */
-	if (port->rs485.flags & SER_RS485_ENABLED &&
-	    imx_uart_readl(sport, USR2) & USR2_TXDC) {
-		u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
-		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
-			imx_uart_rts_active(sport, &ucr2);
-		else
-			imx_uart_rts_inactive(sport, &ucr2);
-		imx_uart_writel(sport, ucr2, UCR2);
+	usr2 = imx_uart_readl(sport, USR2);
+	if (!(usr2 & USR2_TXDC)) {
+		/* The shifter is still busy, so retry once TC triggers */
+		return;
+	}
 
-		imx_uart_start_rx(port);
+	ucr4 = imx_uart_readl(sport, UCR4);
+	ucr4 &= ~UCR4_TCEN;
+	imx_uart_writel(sport, ucr4, UCR4);
 
-		ucr4 = imx_uart_readl(sport, UCR4);
-		ucr4 &= ~UCR4_TCEN;
-		imx_uart_writel(sport, ucr4, UCR4);
+	/* in rs485 mode disable transmitter */
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		if (sport->tx_state == SEND) {
+			sport->tx_state = WAIT_AFTER_SEND;
+			start_hrtimer_ms(&sport->trigger_stop_tx,
+					 port->rs485.delay_rts_after_send);
+			return;
+		}
+
+		if (sport->tx_state == WAIT_AFTER_RTS ||
+		    sport->tx_state == WAIT_AFTER_SEND) {
+			u32 ucr2;
+
+			hrtimer_try_to_cancel(&sport->trigger_start_tx);
+
+			ucr2 = imx_uart_readl(sport, UCR2);
+			if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+				imx_uart_rts_active(sport, &ucr2);
+			else
+				imx_uart_rts_inactive(sport, &ucr2);
+			imx_uart_writel(sport, ucr2, UCR2);
+
+			imx_uart_start_rx(port);
+
+			sport->tx_state = OF