diff options
| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-05-28 00:54:08 +0200 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-08-16 08:25:06 -0400 |
| commit | cf61375fb14bbd7734c42df8a03e4efae6419583 (patch) | |
| tree | 3a064213ef7ae984b9e7c047bc85c383c350713d /drivers/tty | |
| parent | ebe139836e17beea5f6742f7c6e11a7cd9d053de (diff) | |
tty/serial: atmel: fix RS485 half duplex with DMA
[ Upstream commit 0058f0871efe7b01c6f2b3046c68196ab73e96da ]
When using DMA, half duplex doesn't work properly because rx is not stopped
before starting tx. Ensure we call atmel_stop_rx() in the DMA case.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/atmel_serial.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 57687d13ff0f..baa888caa964 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -431,19 +431,21 @@ static void atmel_start_tx(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (atmel_use_pdc_tx(port)) { - if (atmel_uart_readl(port, ATMEL_PDC_PTSR) & ATMEL_PDC_TXTEN) - /* The transmitter is already running. Yes, we - really need this.*/ - return; + if (atmel_use_pdc_tx(port) && (atmel_uart_readl(port, ATMEL_PDC_PTSR) + & ATMEL_PDC_TXTEN)) + /* The transmitter is already running. Yes, we + really need this.*/ + return; + if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port)) if ((port->rs485.flags & SER_RS485_ENABLED) && !(port->rs485.flags & SER_RS485_RX_DURING_TX)) atmel_stop_rx(port); + if (atmel_use_pdc_tx(port)) /* re-enable PDC transmit */ atmel_uart_writel(port, ATMEL_PDC_PTCR, ATMEL_PDC_TXTEN); - } + /* Enable interrupts */ atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); } |