When you try to enable the SPI slave module, the SS line can appear busy. To prevent transmitting incorrect data, the DLN adapter idles until the SS line is released (drives high). Only then, the SPI slave can be enabled.
To limit the idle time, you can specify the idle timeout value in milliseconds (ms) by calling the DlnSpiSlaveSetSSIdleTimeout() function. The default value is 100ms. The idle timeout can be from 1ms to 1000ms. If during the specified idle timeout the SS line was not released, the DlnSpiSlaveEnable() function returns the DLN_RES_SPI_SLAVE_SS_IDLE_TIMEOUT error.
For details about idle event timeout, read DLN_SPI_SLAVE_EVENT_IDLE Events.