From c39998a1541ec1fa1e33f154ef34c0b68ec5b217 Mon Sep 17 00:00:00 2001 From: Mark Date: Sun, 12 Aug 2018 11:47:16 -0400 Subject: [PATCH] tty: serial: 8250: Revert NXP SC16C2552 workaround commit 47ac76662ca9c5852fd353093f19de3ae85f2e66 upstream. 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 Fixes: ecb988a3b798 ("tty: serial: 8250: 8250_core: NXP SC16C2552 workaround") Cc: stable Signed-off-by: Greg Kroah-Hartman --- 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 5d9038a..5b54439 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -83,8 +83,7 @@ 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, }, -- 2.7.4