[PATCH 4.14 193/237] tty/serial: atmel: manage shutdown in case of RS485 or ISO7816 mode

Greg Kroah-Hartman
2020-02-27T14:32:12Z

From: Nicolas Ferre <nicolas.ferre@microchip.com>

commit 04b5bfe3dc94e64d0590c54045815cb5183fb095 upstream.

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@microchip.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200210152053.8289-1-nicolas.ferre@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/tty/serial/atmel_serial.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -498,7 +498,8 @@ static void atmel_stop_tx(struct uart_po
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);

}