Merge tag 'tty-6.8-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial fixes from Greg KH:
 "Here are some small remaining tty/serial driver fixes. Included in
  here is fixes for:

   - vt unicode buffer corruption fix

   - imx serial driver fixes, again

   - port suspend fix

   - 8250_dw driver fix

   - fsl_lpuart driver fix

   - revert for the qcom_geni_serial driver to fix a reported regression

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

* tag 'tty-6.8-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "tty: serial: simplify qcom_geni_serial_send_chunk_fifo()"
  tty: serial: fsl_lpuart: avoid idle preamble pending if CTS is enabled
  vt: fix unicode buffer corruption when deleting characters
  serial: port: Don't suspend if the port is still busy
  serial: 8250_dw: Do not reclock if already at correct rate
  tty: serial: imx: Fix broken RS485

1 files changed, 18 insertions, 4 deletions

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 4aa72d5aeafb..e14813250616 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -462,8 +462,7 @@ static void imx_uart_stop_tx(struct uart_port *port)
 	}
 }
 
-/* called with port.lock taken and irqs off */
-static void imx_uart_stop_rx(struct uart_port *port)
+static void imx_uart_stop_rx_with_loopback_ctrl(struct uart_port *port, bool loopback)
 {
 	struct imx_port *sport = (struct imx_port *)port;
 	u32 ucr1, ucr2, ucr4, uts;
@@ -485,7 +484,7 @@ static void imx_uart_stop_rx(struct uart_port *port)
 	/* See SER_RS485_ENABLED/UTS_LOOP comment in imx_uart_probe() */
 	if (port->rs485.flags & SER_RS485_ENABLED &&
 	    port->rs485.flags & SER_RS485_RTS_ON_SEND &&
-	    sport->have_rtscts && !sport->have_rtsgpio) {
+	    sport->have_rtscts && !sport->have_rtsgpio && loopback) {
 		uts = imx_uart_readl(sport, imx_uart_uts_reg(sport));
 		uts |= UTS_LOOP;
 		imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
@@ -498,6 +497,16 @@ static void imx_uart_stop_rx(struct uart_port *port)
 }
 
 /* called with port.lock taken and irqs off */
+static void imx_uart_stop_rx(struct uart_port *port)
+{
+	/*
+	 * Stop RX and enable loopback in order to make sure RS485 bus
+	 * is not blocked. Se comment in imx_uart_probe().
+	 */
+	imx_uart_stop_rx_with_loopback_ctrl(port, true);
+}
+
+/* called with port.lock taken and irqs off */
 static void imx_uart_enable_ms(struct uart_port *port)
 {
 	struct imx_port *sport = (struct imx_port *)port;
@@ -682,9 +691,14 @@ static void imx_uart_start_tx(struct uart_port *port)
 				imx_uart_rts_inactive(sport, &ucr2);
 			imx_uart_writel(sport, ucr2, UCR2);
 
+			/*
+			 * Since we are about to transmit we can not stop RX
+			 * with loopback enabled because that will make our
+			 * transmitted data being just looped to RX.
+			 */
 			if (!(port->rs485.flags & SER_RS485_RX_DURING_TX) &&
 			    !port->rs485_rx_during_tx_gpio)
-				imx_uart_stop_rx(port);
+				imx_uart_stop_rx_with_loopback_ctrl(port, false);
 
 			sport->tx_state = WAIT_AFTER_RTS;