Example to reproduce 9-bit spi data corruption on ESP32-S3

spi_ninebit_test_main.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/spi_master.h"
#include "driver/gpio.h"

#include "sdkconfig.h"
#include "esp_log.h"


#ifdef CONFIG_IDF_TARGET_ESP32
#  define SPI_HOST    HSPI_HOST
#  define PIN_NUM_MISO 18
#  define PIN_NUM_MOSI 23
#  define PIN_NUM_CLK  19
#  define PIN_NUM_CS   13

#elif CONFIG_IDF_TARGET_ESP32S3
#  define SPI_HOST    SPI2_HOST
#  define PIN_NUM_MISO 13
#  define PIN_NUM_MOSI 11
#  define PIN_NUM_CLK  12
#  define PIN_NUM_CS   10

#endif


static const char TAG[] = "main";

void app_main(void)
{
    esp_err_t ret;

    // Initialise bus
    ESP_LOGI(TAG, "Initializing bus SPI%d...", SPI_HOST+1);
    spi_bus_config_t buscfg={
        .miso_io_num = PIN_NUM_MISO,
        .mosi_io_num = PIN_NUM_MOSI,
        .sclk_io_num = PIN_NUM_CLK,
        .quadwp_io_num = -1,
        .quadhd_io_num = -1,
        .max_transfer_sz = 32,
    };

    ret = spi_bus_initialize(SPI_HOST, &buscfg, SPI_DMA_CH_AUTO);
    ESP_ERROR_CHECK(ret);


    // Initialise device
    ESP_LOGI(TAG, "Initializing device");
    spi_device_handle_t spiDevice;
    spi_device_interface_config_t deviceConfig = {
            .command_bits = 0,
            .address_bits = 0,
            .dummy_bits = 0,
            .mode = 0,
            .duty_cycle_pos = 0,
            .cs_ena_pretrans = 0,
            .cs_ena_posttrans = 0,
            .clock_speed_hz = 100000,
            .input_delay_ns = 0,
            .spics_io_num = PIN_NUM_CS,
            .flags = 0,
            .queue_size = 200,
    };
    ESP_ERROR_CHECK(spi_bus_add_device(SPI_HOST, &deviceConfig, &spiDevice));   
    
    // Send 9-bits of data, all ones
    ESP_LOGI(TAG, "Sending data");
    uint8_t testData[2] = {0xff, 0xff};
    spi_transaction_t transaction = {
            .flags = 0,
            .cmd = 0,
            .addr = 0,
            .length = 9,
            .rxlength = 0,
            .tx_buffer = testData,
    };
    ESP_ERROR_CHECK(spi_device_transmit(spiDevice, &transaction));
    
    while (1) {
        // Add your main loop handling code here.
        vTaskDelay(1);
    }
}