patch "Revert NXP SC16C2552 workaround" added to tty-testing

patch "Revert NXP SC16C2552 workaround" added to tty-testing

[gregkh]

This is a note to let you know that I've just added the patch titled

    Revert NXP SC16C2552 workaround

to my tty git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the tty-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


>From 09c46f3f2f82df132e97ee21702e7a31d6143ed6 Mon Sep 17 00:00:00 2001
From: Mark <dmarkh@cfl.rr.com>
Date: Sun, 12 Aug 2018 11:47:16 -0400
Subject: Revert NXP SC16C2552 workaround

Revert commit ecb988a3b7985913d1f0112f66667cdd15e40711: tty: serial:
8250: 8250_core: NXP SC16C2552 workaround

The above commit causes userland application to no longer write
correctly its first write to a dumb terminal connected to /dev/ttyS0.
This commit seems to be the culprit. It's as though the TX FIFO is being
reset during that write. What should be displayed is:

PSW 80000000 INST 00000000                           HALT
//

What is displayed is some variation of:

T 00000000           HAL//

Reverting this commit via this patch fixes my problem.

Signed-off-by: Mark Hounschell <dmarkh@cfl.rr.com>
Fixes: ecb988a3b798 ("tty: serial: 8250: 8250_core: NXP SC16C2552 workaround")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/8250/8250_port.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 8d863004c0da..3f779d25ec0c 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -90,8 +90,7 @@ static const struct serial8250_config uart_config[] = {
 		.name		= "16550A",
 		.fifo_size	= 16,
 		.tx_loadsz	= 16,
-		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
-				  UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
 		.rxtrig_bytes	= {1, 4, 8, 14},
 		.flags		= UART_CAP_FIFO,
 	},
-- 
2.18.0