linux-kernel - [PATCH] tty/serial: atmel: manage shutdown in case of RS485 or ISO7816 mode

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Message-ID: <20200210152053.8289-1-nicolas.ferre@microchip.com>
Date:   Mon, 10 Feb 2020 16:20:53 +0100
From:   Nicolas Ferre <nicolas.ferre@...rochip.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Richard Genoud <richard.genoud@...il.com>,
        <linux-serial@...r.kernel.org>
CC:     Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Ludovic Desroches <ludovic.desroches@...rochip.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>,
        Codrin Ciubotariu <codrin.ciubotariu@...rochip.com>,
        Nicolas Ferre <nicolas.ferre@...rochip.com>
Subject: [PATCH] tty/serial: atmel: manage shutdown in case of RS485 or ISO7816 mode

In atmel_shutdown() we call atmel_stop_rx() and atmel_stop_tx() functions.
Prevent the rx restart that is implemented in RS485 or ISO7816 modes when
calling atmel_stop_tx() by using the atomic information tasklet_shutdown
that is already in place for this purpose.

Fixes: 98f2082c3ac4 ("tty/serial: atmel: enforce tasklet init and termination sequences")
Signed-off-by: Nicolas Ferre <nicolas.ferre@...rochip.com>
---
 drivers/tty/serial/atmel_serial.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index c15c398c88a9..a39c87a7c2e1 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -570,7 +570,8 @@ static void atmel_stop_tx(struct uart_port *port)
 	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
 
 	if (atmel_uart_is_half_duplex(port))
-		atmel_start_rx(port);
+		if (!atomic_read(&atmel_port->tasklet_shutdown))
+			atmel_start_rx(port);
 
 }
 
-- 
2.17.1