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From: Sherry Sun <sherry.sun@nxp.com>
To: gregkh@linuxfoundation.org, jirislaby@kernel.org, michael@walle.cc
Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-imx@nxp.com
Subject: [PATCH 2/2] tty: serial: fsl_lpuart: writing a 1 and then a 0 to trigger a break character
Date: Fri, 15 Jul 2022 10:59:44 +0800	[thread overview]
Message-ID: <20220715025944.11076-3-sherry.sun@nxp.com> (raw)
In-Reply-To: <20220715025944.11076-1-sherry.sun@nxp.com>

According to the lpuart reference manual, need to writing a 1 and then a
0 to the UARTCTRL_SBK field queues a break character in the transmit
data stream. Only writing a 1 cannot trigger the break character, so fix
it.

Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support")
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
---
 drivers/tty/serial/fsl_lpuart.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index b6365566a460..8a4aae7dbd99 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1486,7 +1486,7 @@ static void lpuart32_break_ctl(struct uart_port *port, int break_state)
 	temp = lpuart32_read(port, UARTCTRL) & ~UARTCTRL_SBK;
 
 	if (break_state != 0)
-		temp |= UARTCTRL_SBK;
+		lpuart32_write(port, temp | UARTCTRL_SBK, UARTCTRL);
 
 	lpuart32_write(port, temp, UARTCTRL);
 }
-- 
2.17.1


  parent reply	other threads:[~2022-07-15  3:01 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-15  2:59 [PATCH 0/2] fsl_lpuart: fix the bugs in received break signal count and send break signal Sherry Sun
2022-07-15  2:59 ` [PATCH 1/2] tty: serial: fsl_lpuart: correct the count of break characters Sherry Sun
2022-07-15  6:58   ` Michael Walle
2022-07-15  7:22     ` Sherry Sun
2022-07-15 12:33   ` Michael Walle
2022-07-15  2:59 ` Sherry Sun [this message]
2022-07-15  6:47   ` [PATCH 2/2] tty: serial: fsl_lpuart: writing a 1 and then a 0 to trigger a break character Michael Walle
2022-07-15  7:20     ` Sherry Sun
2022-07-15  7:42       ` Michael Walle
2022-07-15  9:18         ` Sherry Sun
2022-07-15 11:52           ` Michael Walle
2022-07-18  7:02             ` Jiri Slaby
2022-07-22  9:41               ` Sherry Sun

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