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| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-05-28 00:54:08 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-11-20 01:16:42 +0000 |
| commit | 1d1891b424f02e68c2115092cbd3bad6b2af4fe6 (patch) | |
| tree | fef040a2d6f64e895d4b2da9c5a1647748315e13 /drivers/tty | |
| parent | c00c077d747e4ef053a8e877f061953380c4fe8a (diff) | |
| download | linux-stable-1d1891b424f02e68c2115092cbd3bad6b2af4fe6.tar.gz linux-stable-1d1891b424f02e68c2115092cbd3bad6b2af4fe6.tar.bz2 linux-stable-1d1891b424f02e68c2115092cbd3bad6b2af4fe6.zip | |
tty/serial: atmel: fix RS485 half duplex with DMA
commit 0058f0871efe7b01c6f2b3046c68196ab73e96da upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16:
- Adjust context
- Keep using UART_GET_PTSR()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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 0d39ae4ff533..d806657ca53e 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -434,19 +434,21 @@ 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 (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) - /* The transmitter is already running. Yes, we - really need this.*/ - return; + if (atmel_use_pdc_tx(port) && (UART_GET_PTSR(port) + & 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 ((atmel_port->rs485.flags & SER_RS485_ENABLED) && !(atmel_port->rs485.flags & SER_RS485_RX_DURING_TX)) atmel_stop_rx(port); + if (atmel_use_pdc_tx(port)) /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - } + /* Enable interrupts */ UART_PUT_IER(port, atmel_port->tx_done_mask); } |