Re: [PATCH 1/2] tty/serial: atmel: Add is_half_duplex helper

From: Richard Genoud
Date: Mon Mar 18 2019 - 09:41:47 EST


[ adding Gil Weber in Cc: ]

Le 15/03/2019 Ã 10:23, Razvan Stefanescu a ÃcritÂ:
> Use a helper function to check that a port needs to use half duplex
> communication, replacing several occurrences of multi-line bit checking.
>
> Signed-off-by: Razvan Stefanescu <razvan.stefanescu@xxxxxxxxxxxxx>
> ---
> drivers/tty/serial/atmel_serial.c | 27 ++++++++++++++-------------
> 1 file changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 05147fe24343..a6577b1c4461 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -231,6 +231,13 @@ static inline void atmel_uart_write_char(struct uart_port *port, u8 value)
> __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)) ||
> + (port->iso7816.flags & SER_ISO7816_ENABLED);
> +}
> +
> #ifdef CONFIG_SERIAL_ATMEL_PDC
> static bool atmel_use_pdc_rx(struct uart_port *port)
> {
> @@ -608,10 +615,10 @@ static void atmel_stop_tx(struct uart_port *port)
> /* 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)) ||
> - port->iso7816.flags & SER_ISO7816_ENABLED)
> - atmel_start_rx(port);
> + if (atmel_uart_is_half_duplex(port))
> + if (!atomic_read(&atmel_port->tasklet_shutdown))
This check wasn't there before.
If it's really needed, please insert it in another patch and explain why
it's needed.

> + atmel_start_rx(port);
> +
> }
>
> /*
> @@ -628,9 +635,7 @@ static void atmel_start_tx(struct uart_port *port)
> 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)) ||
> - port->iso7816.flags & SER_ISO7816_ENABLED)
> + if (atmel_uart_is_half_duplex(port))
> atmel_stop_rx(port);
>
> if (atmel_use_pdc_tx(port))
> @@ -928,9 +933,7 @@ static void atmel_complete_tx_dma(void *arg)
> */
> 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)) ||
> - port->iso7816.flags & SER_ISO7816_ENABLED) {
> + else if (atmel_uart_is_half_duplex(port)) {
> /* DMA done, stop TX, start RX for RS485 */
> atmel_start_rx(port);
> }
> @@ -1508,9 +1511,7 @@ static void atmel_tx_pdc(struct uart_port *port)
> 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)) ||
> - port->iso7816.flags & SER_ISO7816_ENABLED) {
> + if (atmel_uart_is_half_duplex(port)) {
> /* DMA done, stop TX, start RX for RS485 */
> atmel_start_rx(port);
> }
>