Re: [PATCH v3 3/6] hw/char: cadence_uart: Move clock/reset check to uart_can_receive()

[Alistair Francis]

On Wed, Sep 1, 2021 at 10:49 PM Bin Meng <bmeng.cn@gmail.com> wrote:
>
> Currently the clock/reset check is done in uart_receive(), but we
> can move the check to uart_can_receive() which is earlier.
>
> Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

>
> ---
>
> (no changes since v2)
>
> Changes in v2:
> - avoid declaring variables mid-scope
>
>  hw/char/cadence_uart.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/hw/char/cadence_uart.c b/hw/char/cadence_uart.c
> index 154be34992..fff8be3619 100644
> --- a/hw/char/cadence_uart.c
> +++ b/hw/char/cadence_uart.c
> @@ -235,8 +235,16 @@ static void uart_parameters_setup(CadenceUARTState *s)
>  static int uart_can_receive(void *opaque)
>  {
>      CadenceUARTState *s = opaque;
> -    int ret = MAX(CADENCE_UART_RX_FIFO_SIZE, CADENCE_UART_TX_FIFO_SIZE);
> -    uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
> +    int ret;
> +    uint32_t ch_mode;
> +
> +    /* ignore characters when unclocked or in reset */
> +    if (!clock_is_enabled(s->refclk) || device_is_in_reset(DEVICE(s))) {
> +        return 0;
> +    }
> +
> +    ret = MAX(CADENCE_UART_RX_FIFO_SIZE, CADENCE_UART_TX_FIFO_SIZE);
> +    ch_mode = s->r[R_MR] & UART_MR_CHMODE;
>
>      if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
>          ret = MIN(ret, CADENCE_UART_RX_FIFO_SIZE - s->rx_count);
> @@ -358,11 +366,6 @@ static void uart_receive(void *opaque, const uint8_t 
> *buf, int size)
>      CadenceUARTState *s = opaque;
>      uint32_t ch_mode = s->r[R_MR] & UART_MR_CHMODE;
>
> -    /* ignore characters when unclocked or in reset */
> -    if (!clock_is_enabled(s->refclk) || device_is_in_reset(DEVICE(s))) {
> -        return;
> -    }
> -
>      if (ch_mode == NORMAL_MODE || ch_mode == ECHO_MODE) {
>          uart_write_rx_fifo(opaque, buf, size);
>      }
> --
> 2.25.1
>
>