Re: [PATCH v3] serial: uartps: Add TACTIVE bit in cdns_uart_tx_empty function

[Maarten Brock]

On 2020-01-31 12:04, Shubhrajyoti Datta wrote:
>  drivers/tty/serial/xilinx_uartps.c | 22 +++++-----------------
>  1 file changed, 5 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/tty/serial/xilinx_uartps.c
> b/drivers/tty/serial/xilinx_uartps.c
> index ed2f325..ebd0a74 100644
> --- a/drivers/tty/serial/xilinx_uartps.c
> +++ b/drivers/tty/serial/xilinx_uartps.c
> @@ -656,8 +655,9 @@ static unsigned int cdns_uart_tx_empty(struct
> uart_port *port)
>  {
>  	unsigned int status;
>
> -	status = readl(port->membase + CDNS_UART_SR) &
> -				CDNS_UART_SR_TXEMPTY;
> +	status = ((readl(port->membase + CDNS_UART_SR) &
> +				(CDNS_UART_SR_TXEMPTY |
> +				CDNS_UART_SR_TACTIVE)) == CDNS_UART_SR_TXEMPTY);
>  	return status ? TIOCSER_TEMT : 0;
>  }

These lines look pretty incomprehensible.
How about rewriting it like this?

    status = readl(port->membase + CDNS_UART_SR) &
             (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE);
    return (status == CDNS_UART_SR_TXEMPTY) ? TIOCSER_TEMT : 0;

Maarten