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| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-05-28 00:54:08 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-08-20 18:10:49 +0200 |
| commit | a5d510e933f28e8a00856072f38f34b0c73a525a (patch) | |
| tree | 22d3f44294aac0b896587cc804cd3cff5475e692 | |
| parent | f28bd6bfdc4f57d8cee8c574603fbed6bf26ec12 (diff) | |
| download | linux-stable-a5d510e933f28e8a00856072f38f34b0c73a525a.tar.gz linux-stable-a5d510e933f28e8a00856072f38f34b0c73a525a.tar.bz2 linux-stable-a5d510e933f28e8a00856072f38f34b0c73a525a.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>
| -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 954941dd8124..f9c798cba83f 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -482,19 +482,21 @@ 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); } |