[PATCH v4 1/7] serial: sh-sci: Drop TE disable at end of transmission on SCI

[Diogo Ivo <diogo.ivo.sx@renesas.com>]

From: Biju Das <biju.das.jz@bp.renesas.com>

Commit f06c2a9000eb ("tty: serial: sh-sci: Fix end of transmission on
SCI") made sci_transmit_chars() clear SCSCR.TE and return early on
PORT_SCI once the transmit FIFO is empty.

The hardware manual does not describe disabling the transmitter to end
a transmission, so this special case has no basis in the documented
programming sequence. Remove it and let SCI follow the same path as the
other port types. A plain revert no longer applies because the driver
now uses a kfifo, so the code is removed by hand.

Fixes: f06c2a9000eb ("tty: serial: sh-sci: Fix end of transmission on SCI")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Diogo Ivo <diogo.ivo.sx@renesas.com>
---
 drivers/tty/serial/sh-sci.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index bd58bbfa65aa..9eb297dbc901 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1036,13 +1036,6 @@ static void sci_transmit_chars(struct uart_port *port)
 			c = port->x_char;
 			port->x_char = 0;
 		} else if (stopped || !kfifo_get(&tport->xmit_fifo, &c)) {
-			if (s->type == PORT_SCI &&
-			    kfifo_is_empty(&tport->xmit_fifo)) {
-				ctrl = sci_serial_in(port, SCSCR);
-				ctrl &= ~SCSCR_TE;
-				sci_serial_out(port, SCSCR, ctrl);
-				return;
-			}
 			break;
 		}
 

-- 
2.56.0