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authorDavid S. Miller <davem@davemloft.net>2016-10-30 19:42:58 +0300
committerDavid S. Miller <davem@davemloft.net>2016-10-30 19:42:58 +0300
commit27058af401e49d88a905df000dd26f443fcfa8ce (patch)
tree819f32113d3b8374b9fbf72e2202d4c4d4511a60 /drivers/tty/serial/atmel_serial.c
parent357f4aae859b5d74554b0ccbb18556f1df4166c3 (diff)
parent2a26d99b251b8625d27aed14e97fc10707a3a81f (diff)
downloadlinux-27058af401e49d88a905df000dd26f443fcfa8ce.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Mostly simple overlapping changes. For example, David Ahern's adjacency list revamp in 'net-next' conflicted with an adjacency list traversal bug fix in 'net'. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/tty/serial/atmel_serial.c')
-rw-r--r--drivers/tty/serial/atmel_serial.c26
1 files changed, 22 insertions, 4 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index fd8aa1f4ba78..168b10cad47b 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2132,11 +2132,29 @@ 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) */
- 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 {
+ if (atmel_use_fifo(port) &&
+ !mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS)) {
+ /*
+ * with ATMEL_US_USMODE_HWHS set, the controller will
+ * be able to drive the RTS pin high/low when the RX
+ * FIFO is above RXFTHRES/below RXFTHRES2.
+ * It will also disable the transmitter when the CTS
+ * pin is high.
+ * This mode is not activated if CTS pin is a GPIO
+ * because in this case, the transmitter is always
+ * disabled (there must be an internal pull-up
+ * responsible for this behaviour).
+ * If the RTS pin is a GPIO, the controller won't be
+ * able to drive it according to the FIFO thresholds,
+ * but it will be handled by the driver.
+ */
mode |= ATMEL_US_USMODE_HWHS;
+ } else {
+ /*
+ * For platforms without FIFO, the flow control is
+ * handled by the driver.
+ */
+ mode |= ATMEL_US_USMODE_NORMAL;
}
} else {
/* RS232 without hadware handshake */