On Fri, Feb 05, 2021 at 12:08:55PM +0100, Alain Volmat wrote:
> On 0 byte transfer request, return straight from the
> xfer function after finalizing the transfer.

> +	if (transfer->len == 0) {
> +		spi_finalize_current_transfer(master);
> +		return 0;

The driver only needs to finalize the transfer if it returned a value
greater than 0, returning 0 indicates that the transfer is already done.