On Thu, Jan 07, 2021 at 02:16:41PM +0800, [email protected] wrote:
> From: Qiumiao Zhang <[email protected]>
> 
> make pl011 serial port support 485 mode full duplex communication
> 
> Signed-off-by: Qiumiao Zhang <[email protected]>
> ---
> Changes in v2:
>  - Fix two compilation errors

What changed from the version you sent yesterday with this same subject
line?

>  drivers/tty/serial/amba-pl011.c | 38 +++++++++++++++++++++++++++++++++
>  1 file changed, 38 insertions(+)
> 
> diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
> index c255476cce28..f6a7fe61e699 100644
> --- a/drivers/tty/serial/amba-pl011.c
> +++ b/drivers/tty/serial/amba-pl011.c
> @@ -44,6 +44,7 @@
> 
>  #include "amba-pl011.h"
> 
> +#define ISEMPTY                      1
>  #define UART_NR                      14
> 
>  #define SERIAL_AMBA_MAJOR    204
> @@ -1284,14 +1285,33 @@ static inline bool pl011_dma_rx_running(struct 
> uart_amba_port *uap)
>  #define pl011_dma_flush_buffer       NULL
>  #endif
> 
> +static unsigned int pl011_tx_empty(struct uart_port *port);
> +
>  static void pl011_stop_tx(struct uart_port *port)
>  {
> +     unsigned int cr;
> +     unsigned int result;

But below the uap definition please, like kernel style normally is.

>       struct uart_amba_port *uap =
>           container_of(port, struct uart_amba_port, port);
> 
>       uap->im &= ~UART011_TXIM;
>       pl011_write(uap->im, uap, REG_IMSC);
>       pl011_dma_tx_stop(uap);
> +     if (port->rs485.flags & SER_RS485_ENABLED) {
> +             while(1) {
> +                     result = pl011_tx_empty(port);
> +                     if (ISEMPTY == result) {
> +                             break;
> +                     }

It's not ok to busy loop forever, sorry.

> +             }
> +             cr = pl011_read(uap, REG_CR);
> +             if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) {
> +                     cr |= UART011_CR_RTS;
> +             } else {
> +                     cr &= ~UART011_CR_RTS;
> +             }

Did you run checkpatch on this code?  Please fix up.

thanks,

greg k-h

Reply via email to