Merge tag 'tty-5.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 5.5-rc3.

  Only four small patches here:

   - atmel serial driver fix

   - msm_serial driver fix

   - sprd serial driver fix

   - tty core port fix

  The last tty core fix should resolve a long-standing bug with a race
  at port creation time that some people would see, and Sudip finally
  tracked down.

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

* tag 'tty-5.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty/serial: atmel: fix out of range clock divider handling
  tty: link tty and port before configuring it as console
  serial: sprd: Add clearing break interrupt operation
  tty: serial: msm_serial: Fix lockup for sysrq and oops

5 files changed, 39 insertions, 24 deletions

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index a8dc8af83f39..1ba9bc667e13 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2270,27 +2270,6 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
 		mode |= ATMEL_US_USMODE_NORMAL;
 	}
 
-	/* set the mode, clock divisor, parity, stop bits and data size */
-	atmel_uart_writel(port, ATMEL_US_MR, mode);
-
-	/*
-	 * when switching the mode, set the RTS line state according to the
-	 * new mode, otherwise keep the former state
-	 */
-	if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) {
-		unsigned int rts_state;
-
-		if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
-			/* let the hardware control the RTS line */
-			rts_state = ATMEL_US_RTSDIS;
-		} else {
-			/* force RTS line to low level */
-			rts_state = ATMEL_US_RTSEN;
-		}
-
-		atmel_uart_writel(port, ATMEL_US_CR, rts_state);
-	}
-
 	/*
 	 * Set the baud rate:
 	 * Fractional baudrate allows to setup output frequency more
@@ -2317,6 +2296,28 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
 		atmel_uart_writel(port, ATMEL_US_BRGR, quot);
+
+	/* set the mode, clock divisor, parity, stop bits and data size */
+	atmel_uart_writel(port, ATMEL_US_MR, mode);
+
+	/*
+	 * when switching the mode, set the RTS line state according to the
+	 * new mode, otherwise keep the former state
+	 */
+	if ((old_mode & ATMEL_US_USMODE) != (mode & ATMEL_US_USMODE)) {
+		unsigned int rts_state;
+
+		if ((mode & ATMEL_US_USMODE) == ATMEL_US_USMODE_HWHS) {
+			/* let the hardware control the RTS line */
+			rts_state = ATMEL_US_RTSDIS;
+		} else {
+			/* force RTS line to low level */
+			rts_state = ATMEL_US_RTSEN;
+		}
+
+		atmel_uart_writel(port, ATMEL_US_CR, rts_state);
+	}
+
 	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
 	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
 	atmel_port->tx_stopped = false;
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index 1cbae0768b1f..f6c45a796433 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -1580,6 +1580,7 @@ static void __msm_console_write(struct uart_port *port, const char *s,
 	int num_newlines = 0;
 	bool replaced = false;
 	void __iomem *tf;
+	int locked = 1;
 
 	if (is_uartdm)
 		tf = port->membase + UARTDM_TF;
@@ -1592,7 +1593,13 @@ static void __msm_console_write(struct uart_port *port, const char *s,
 			num_newlines++;
 	count += num_newlines;
 
-	spin_lock(&port->lock);
+	if (port->sysrq)
+		locked = 0;
+	else if (oops_in_progress)
+		locked = spin_trylock(&port->lock);
+	else
+		spin_lock(&port->lock);
+
 	if (is_uartdm)
 		msm_reset_dm_count(port, count);
 
@@ -1628,7 +1635,9 @@ static void __msm_console_write(struct uart_port *port, const char *s,
 		iowrite32_rep(tf, buf, 1);
 		i += num_chars;
 	}
-	spin_unlock(&port->lock);
+
+	if (locked)
+		spin_unlock(&port->lock);
 }
 
 static void msm_console_write(struct console *co, const char *s,
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index b0a6eb106edb..7c2782785736 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2834,6 +2834,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 	if (uport->cons && uport->dev)
 		of_console_check(uport->dev->of_node, uport->cons->name, uport->line);
 
+	tty_port_link_device(port, drv->tty_driver, uport->line);
 	uart_configure_port(drv, state, uport);
 
 	port->console = uart_console(uport);
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
index 31df23502562..f60a59d9bf27 100644
--- a/drivers/tty/serial/sprd_serial.c
+++ b/drivers/tty/serial/sprd_serial.c
@@ -679,6 +679,9 @@ static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
 	if (ims & SPRD_IMSR_TIMEOUT)
 		serial_out(port, SPRD_ICLR, SPRD_ICLR_TIMEOUT);
 
+	if (ims & SPRD_IMSR_BREAK_DETECT)
+		serial_out(port, SPRD_ICLR, SPRD_IMSR_BREAK_DETECT);
+
 	if (ims & (SPRD_IMSR_RX_FIFO_FULL | SPRD_IMSR_BREAK_DETECT |
 		   SPRD_IMSR_TIMEOUT))
 		sprd_rx(port);
diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
index 044c3cbdcfa4..5023c85ebc6e 100644
--- a/drivers/tty/tty_port.c
+++ b/drivers/tty/tty_port.c
@@ -89,7 +89,8 @@ void tty_port_link_device(struct tty_port *port,
 {
 	if (WARN_ON(index >= driver->num))
 		return;
-	driver->ports[index] = port;
+	if (!driver->ports[index])
+		driver->ports[index] = port;
 }
 EXPORT_SYMBOL_GPL(tty_port_link_device);