4.19-stable review patch. If anyone has any objections, please let me know.
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From: Razvan Stefanescu razvan.stefanescu@microchip.com
commit f3040983132bf3477acd45d2452a906e67c2fec9 upstream.
Use a helper function to check that a port needs to use half duplex communication, replacing several occurrences of multi-line bit checking.
Fixes: b389f173aaa1 ("tty/serial: atmel: RS485 half duplex w/DMA: enable RX after TX is done") Cc: stable stable@vger.kernel.org Signed-off-by: Razvan Stefanescu razvan.stefanescu@microchip.com Acked-by: Richard Genoud richard.genoud@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/serial/atmel_serial.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
--- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -225,6 +225,12 @@ static inline void atmel_uart_write_char __raw_writeb(value, port->membase + ATMEL_US_THR); }
+static inline int atmel_uart_is_half_duplex(struct uart_port *port) +{ + return (port->rs485.flags & SER_RS485_ENABLED) && + !(port->rs485.flags & SER_RS485_RX_DURING_TX); +} + #ifdef CONFIG_SERIAL_ATMEL_PDC static bool atmel_use_pdc_rx(struct uart_port *port) { @@ -481,9 +487,9 @@ static void atmel_stop_tx(struct uart_po /* Disable interrupts */ atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
- if ((port->rs485.flags & SER_RS485_ENABLED) && - !(port->rs485.flags & SER_RS485_RX_DURING_TX)) + if (atmel_uart_is_half_duplex(port)) atmel_start_rx(port); + }
/* @@ -500,8 +506,7 @@ static void atmel_start_tx(struct uart_p 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)) + if (atmel_uart_is_half_duplex(port)) atmel_stop_rx(port);
if (atmel_use_pdc_tx(port)) @@ -799,8 +804,7 @@ static void atmel_complete_tx_dma(void * */ if (!uart_circ_empty(xmit)) atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx); - else if ((port->rs485.flags & SER_RS485_ENABLED) && - !(port->rs485.flags & SER_RS485_RX_DURING_TX)) { + else if (atmel_uart_is_half_duplex(port)) { /* DMA done, stop TX, start RX for RS485 */ atmel_start_rx(port); } @@ -1377,8 +1381,7 @@ static void atmel_tx_pdc(struct uart_por atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask); } else { - if ((port->rs485.flags & SER_RS485_ENABLED) && - !(port->rs485.flags & SER_RS485_RX_DURING_TX)) { + if (atmel_uart_is_half_duplex(port)) { /* DMA done, stop TX, start RX for RS485 */ atmel_start_rx(port); }