When transmitting multiple 8-bit words in a SPI transfer, some SPI clients require delay before sending/receiving next word. The following picture shows the delay between words within one SPI transfer on Raspberry Pi:
The upper trace is SPI CLK and lower trace is SPI CS. But there is no such delay on Jetson Nano as shown in the following picture:
For the above picture SPI CLK frequency is 1 MHz, and delay_usecs in struct spi_ioc_transfer is 4us. Changing delay_usecs did not create the delay between words.
Does anyone know how to control the delay between words? Is this a bug in SPI driver?