Merge tag 'tty-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty and serial driver updates from Greg KH:
 "Here's the large TTY and Serial driver update for 4.7-rc1.

  A few new serial drivers are added here, and Peter has fixed a bunch
  of long-standing bugs in the tty layer and serial drivers as normal.
  Full details in the shortlog.

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

* tag 'tty-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (88 commits)
  MAINTAINERS: 8250: remove website reference
  serial: core: Fix port mutex assert if lockdep disabled
  serial: 8250_dw: fix wrong logic in dw8250_check_lcr()
  tty: vt, finish looping on duplicate
  tty: vt, return error when con_startup fails
  QE-UART: add "fsl,t1040-ucc-uart" to of_device_id
  serial: mctrl_gpio: Drop support for out1-gpios and out2-gpios
  serial: 8250dw: Add device HID for future AMD UART controller
  Fix OpenSSH pty regression on close
  serial: mctrl_gpio: add IRQ locking
  serial: 8250: Integrate Fintek into 8250_base
  serial: mps2-uart: add support for early console
  serial: mps2-uart: add MPS2 UART driver
  dt-bindings: document the MPS2 UART bindings
  serial: sirf: Use generic uart-has-rtscts DT property
  serial: sirf: Introduce helper variable struct device_node *np
  serial: mxs-auart: Use generic uart-has-rtscts DT property
  serial: imx: Use generic uart-has-rtscts DT property
  doc: DT: Add Generic Serial Device Tree Bindings
  serial: 8250: of: Make tegra_serial_handle_break() static
  ...

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index d9439e6..954941d 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -274,6 +274,13 @@ static bool atmel_use_dma_rx(struct uart_port *port)
 	return atmel_port->use_dma_rx;
 }
 
+static bool atmel_use_fifo(struct uart_port *port)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+
+	return atmel_port->fifo_size;
+}
+
 static unsigned int atmel_get_lines_status(struct uart_port *port)
 {
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
@@ -2090,7 +2097,12 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
 		mode |= ATMEL_US_USMODE_RS485;
 	} else if (termios->c_cflag & CRTSCTS) {
 		/* RS232 with hardware handshake (RTS/CTS) */
-		mode |= ATMEL_US_USMODE_HWHS;
+		if (atmel_use_dma_rx(port) && !atmel_use_fifo(port)) {
+			dev_info(port->dev, "not enabling hardware flow control because DMA is used");
+			termios->c_cflag &= ~CRTSCTS;
+		} else {
+			mode |= ATMEL_US_USMODE_HWHS;
+		}
 	} else {
 		/* RS232 without hadware handshake */
 		mode |= ATMEL_US_USMODE_NORMAL;