call to BSP_LCD_Init never returns. gets stuck in HAL_DSI_shortwrite

Question

I have been trying to understand how things work on the stm32f69 micro-controller board with cortex m7. I found a tutorial writing hello world on the display but I can get it to work on my board. Here is the code I am using

#include "stm32f769xx.h"
#include "stm32f769i_discovery.h"
#include "stm32f769i_discovery_lcd.h"
#include "stm32f7xx_hal.h"

/* Private function prototypes -----------------------------------------------*/
static void LCD_Config(void);
static void SystemClock_Config(void);
static void Error_Handler(void);
static void CPU_CACHE_Enable(void);

int main(void)
{
    // enable cpu cache
    CPU_CACHE_Enable();
    //
    HAL_Init();

    //
    LCD_Config();

    /* Our main starts here */
    uint16_t ypos = 0, ymax = 0;
    int8_t yincr = 1;
    BSP_LCD_SetTextColor(LCD_COLOR_WHITE);
    BSP_LCD_SetBackColor(LCD_COLOR_BLACK);

    while(1) {
      if(ypos == 0) {
          yincr = 1;
          ymax = BSP_LCD_GetYSize();
      } else {
          yincr = -1;
          ymax = 0;
      }

      for(;yincr == 1 ? ypos < BSP_LCD_GetYSize() - Font24.Height : ypos > 0; ypos+=yincr) {
          BSP_LCD_DisplayStringAt(0, ypos, (uint8_t*)"Hello to everyone!", CENTER_MODE);
      }
    }

    for(;;);
}

/**
  * @brief  System Clock Configuration
  * @param  None
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  HAL_StatusTypeDef ret = HAL_OK;

  /* Enable HSE Oscillator and activate PLL with HSE as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 25;
  RCC_OscInitStruct.PLL.PLLN = 400;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 8;

  ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
  if(ret != HAL_OK)
  {
    while(1) { ; }
  }

  /* Activate the OverDrive to reach the 200 MHz Frequency */
  ret = HAL_PWREx_EnableOverDrive();
  if(ret != HAL_OK)
  {
    while(1) { ; }
  }

  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_6);
  if(ret != HAL_OK)
  {
    while(1) { ; }
  }
}

static void LCD_Config(void)
{
  /* LCD Initialization */
  BSP_LCD_Init();

  /* LCD Initialization */
  BSP_LCD_LayerDefaultInit(0, LCD_FB_START_ADDRESS);

  /* Enable the LCD */
  BSP_LCD_DisplayOn();

  /* Select the LCD Background Layer  */
  BSP_LCD_SelectLayer(0);

  /* Clear the Background Layer */
  BSP_LCD_Clear(LCD_COLOR_BLACK);

  /* Configure the transparency for background */
  BSP_LCD_SetTransparency(0, 100);
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
    /* Turn LED1 on */
    BSP_LED_On(LED1);
    while(1)
    {
    }
}

/**
  * @brief  CPU L1-Cache enable.
  * @param  None
  * @retval None
  */
static void CPU_CACHE_Enable(void)
{
  /* Enable I-Cache */
  SCB_EnableICache();

  /* Enable D-Cache */
  SCB_EnableDCache();
}

When I examined I kept pausing the execution I noticed that that there is one function specifically stalling the execution which is called HAL_DSI_ShortWrite(). Within this function it gets stuck in the following loop

  /* Wait for Command FIFO Empty */
  while((hdsi->Instance->GPSR & DSI_GPSR_CMDFE) == 0)
  {
    /* Check for the Timeout */
    if((HAL_GetTick() - tickstart ) > DSI_TIMEOUT_VALUE)
    {
      /* Process Unlocked */
      __HAL_UNLOCK(hdsi);

      return HAL_TIMEOUT;
    }
  }

which is provided inside the library supplied by the st board manufactor. is there something I should have done before calling BSP_LCD_Init ?

Here is a sample of the stack

Answer 1

So, you garner more information from this (pg 1964), but the long and the short is that you need to configure the clocks. According to the document,

**What programming model sequence should I follow to use HAL drivers ? **

Follow the sequence below to use the APIs provided in the HAL drivers:

1. Call HAL_Init() function to initialize the system (data cache, NVIC priority,...).

2. Initialize the system clock by calling HAL_RCC_OscConfig() followed by HAL_RCC_ClockConfig().

3. Add HAL_IncTick() function under SysTick_Handler() ISR function to enable polling process when using HAL_Delay() function

4. Start initializing your peripheral by calling HAL_PPP_Init().

5. Implement the hardware low level initialization (Peripheral clock, GPIO, DMA ,..) by calling HAL_PPP_MspInit() inxx_hal_msp.c

6. Start your process operation by calling IO operation functions.

This will look something like:

/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
RCC_OscInitTypeDef RCC_OscInitStruct;

/* Enable HSE Oscillator and activate PLL with HSE as source */
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSIState = RCC_HSI_OFF;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 25;
RCC_OscInitStruct.PLL.PLLN = 432;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 9;

HAL_RCC_OscConfig(&RCC_OscInitStruct);

RCC_ClkInitTypeDef RCC_ClkInitStruct;

RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_7);

BSP_LCD_Init();

Depending on your requirements.