From mboxrd@z Thu Jan 1 00:00:00 1970 From: gregkh@linuxfoundation.org (Greg KH) Date: Thu, 12 Jul 2018 16:59:18 +0200 Subject: [PATCH 3/3] tty/serial: atmel: manage shutdown in case of RS485 or ISO7816 mode In-Reply-To: <20180711131638.12622-4-ludovic.desroches@microchip.com> References: <20180711131638.12622-1-ludovic.desroches@microchip.com> <20180711131638.12622-4-ludovic.desroches@microchip.com> Message-ID: <20180712145918.GC22502@kroah.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jul 11, 2018 at 03:16:38PM +0200, Ludovic Desroches wrote: > From: Nicolas Ferre > > 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. > > Signed-off-by: Nicolas Ferre No signed-off-by from you? > --- > drivers/tty/serial/atmel_serial.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c > index 0118b219f3a8..e4f877e1f3c6 100644 > --- a/drivers/tty/serial/atmel_serial.c > +++ b/drivers/tty/serial/atmel_serial.c > @@ -617,7 +617,9 @@ static void atmel_stop_tx(struct uart_port *port) > if (((port->rs485.flags & SER_RS485_ENABLED) && > !(port->rs485.flags & SER_RS485_RX_DURING_TX)) || > port->iso7816.flags & SER_ISO7816_ENABLED) > - atmel_start_rx(port); > + if (!atomic_read(&atmel_port->tasklet_shutdown)) > + atmel_start_rx(port); Is this really ok? No locking needed? What happens if that value is set right after this? thanks, greg k-h