Re: [PATCH 1/2] spi: axiado: merge identical if/else branches in ax_transfer_one()

[Tzu-Hao Wei]

On 7/13/2026 2:08 PM, Babanpreet Singh wrote:
> CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.
> 
> 
> The else-if arm taken for RX-only and full-duplex transfers and the
> trailing else arm in the RX bookkeeping setup of ax_transfer_one()
> have identical bodies, so the second condition has no effect:
> 
>   drivers/spi/spi-axiado.c:433:8-10: WARNING: possible condition with
>   no effect (if == else)
> 
> The trailing else arm (neither TX nor RX buffer) is also unreachable:
> the SPI core only calls the ->transfer_one() callback for transfers
> that carry at least one buffer, see spi_transfer_one_message().
> 
> Merge the two arms into a single else branch and fold their comments.
> No functional change. The redundant condition has been present since
> the driver was added in commit e75a6b00ad79 ("spi: axiado: Add driver
> for Axiado SPI DB controller").
> 
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Julia Lawall <julia.lawall@xxxxxxxx>
> Closes: https://lore.kernel.org/r/202607121827.djB0zLAj-lkp@xxxxxxxxx/
> Assisted-by: Claude:claude-fable-5 [coccinelle]
> Signed-off-by: Babanpreet Singh <bbnpreetsingh@xxxxxxxxx>
> ---
>  drivers/spi/spi-axiado.c | 12 ++++--------
>  1 file changed, 4 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/spi/spi-axiado.c b/drivers/spi/spi-axiado.c
> index 649f149617ce..c4bc7a50d6c9 100644
> --- a/drivers/spi/spi-axiado.c
> +++ b/drivers/spi/spi-axiado.c
> @@ -430,15 +430,11 @@ static int ax_transfer_one(struct spi_controller *ctlr,
>                 /* TX mode: discard all received data */
>                 xspi->rx_discard = transfer->len;
>                 xspi->rx_copy_remaining = 0;
> -       } else if ((!transfer->tx_buf && transfer->rx_buf) ||
> -                  (transfer->tx_buf && transfer->rx_buf)) {
> -               /* RX mode: generate clock by filling TX FIFO with dummy bytes
> -                * Full-duplex mode: generate clock by filling TX FIFO
> -                */
> -               xspi->rx_discard = 0;
> -               xspi->rx_copy_remaining = transfer->len;
>         } else {
> -               /* No TX and RX */
> +               /* RX-only or full-duplex mode: copy received data, with the
> +                * clock generated by filling the TX FIFO (with dummy bytes
> +                * in RX-only mode)
> +                */
>                 xspi->rx_discard = 0;
>                 xspi->rx_copy_remaining = transfer->len;
>         }
> 
> base-commit: 5f1b513690edf51727e6928b97705b6437f9a98e
> --
> 2.43.0
> 
Hi Babanpreet,

Thanks for your contribution. It looks good to me.

Acked-By: Tzu-Hao Wei <twei@xxxxxxxxxx>

Best regards,
TH