CCS/OMAP-L138: C6748 UARTTX interrupt happens only once.

1. UART_BasicExample_lcdkOMAPL138_c674xExampleProject
2. UART_BasicExample_lcdkOMAPL138_c674xTestProject
3. UART_BasicExample_lcdkOMAPL138_c674xDMATestProject

Among these, I tested the Uart Polling method using No.1 and now I'm trying the Interrupt method using No.2.

For interrupt method, I added the source code by referring to ~pdk/packages/ti/csl/example/uart/intr/main.c in Example code 2 (UART_BasicExample_lcdkOMAPL138_c674xTestProject)

The codes added or modified are as follows:

void uartIsr()
{
    static uint32_t txStrLength = sizeof(txArray);
    static uint32_t count       = 0;
    uint32_t        intId       = 0;
    rxByte      = 0;

    intId = UART_intIdentityGet_v0(CSL_UART_2_REGS);
    
    switch(intId)
    {
        case UART_INTID_TX_THRES_REACH:
            if( 0 != txStrLength)
            {
                UART_charPut_v0(CSL_UART_2_REGS, txArray[count]);
                txStrLength--;
                count++;
            }
            else
            {
                UART_intDisable_v0(CSL_UART_2_REGS, UART_INT_THR );
            }

            break;

        case UART_INTID_RX_THRES_REACH:
            buffer[++bufferIdx] = UART_charGetNonBlocking_v0(CSL_UART_2_REGS);
            UART_charPut_v0(CSL_UART_2_REGS, buffer[bufferIdx]);
            break;

        case UART_INTID_RX_LINE_STAT_ERROR:
        case UART_INTID_CHAR_TIMEOUT:
            UART_charGetNonBlocking_v0(CSL_UART_2_REGS);
            break;

        default:
            break;

    }
}

void uart_test(UArg arg0, UArg arg1)
{
    UART_Handle     uart = NULL;
    UART_Params      uartParams;
    int              length = 0;
    uintptr_t         addrDataPrint, addrScanPrompt, addrEchoPrompt;
    UART_Transaction transaction;
    bool             ret = false;
    UART_HwAttrs uart_cfg;

    printf("Starting Uart test \n");
    UART_init();
    UART_socGetInitCfg(uartTestInstance, &uart_cfg);
    UART_osalSemParamsInit(&semParams);
    semParams.mode = SemaphoreP_Mode_BINARY;
    callbackSem = UART_osalCreateBlockingLock(0, &semParams);

    /* UART SoC init configuration */
    UART_initConfig(false);
    UART_Params_init(&uartParams);
    uartParams.baudRate =115200;
    uart_cfg.edmaHandle = NULL;
    uart_cfg.dmaMode = FALSE;
    uart_cfg.enableInterrupt=1; /* Enabling interrupt forcefully */

    /* Get the default UART init configurations */
    UART_socSetInitCfg(uartTestInstance, &uart_cfg);
    uart = UART_open(uartTestInstance, &uartParams);

    if(uart == NULL)
    {
        if(uart)
        {
            UART_close(uart);
        }
    }

    Intc_Init();
    IntEventCombineInit(ECM0_UNUSED, ECM1_UNUSED, C674X_MASK_INT4, ECM3_UNUSED);
    IntEventCombineRegister(69, (c674xISR)uartIsr);
    IntEventCombineAdd(69);
    Intc_SystemEnable();
    UART_intEnable_v0(CSL_UART_2_REGS,(UART_INT_LINE_STAT | UART_INT_THR |
            UART_INT_RHR_CTI) );

    while(1)
    {  
    }
}

I added the following code after seeing ~pdk/packages/ti/csl/example/uart/intr/main.c.

Intc_Init();
IntEventCombineInit(ECM0_UNUSED, ECM1_UNUSED, C674X_MASK_INT4, ECM3_UNUSED);
IntEventCombineRegister(69, (c674xISR)uartIsr);
IntEventCombineAdd(69);
Intc_SystemEnable();
UART_intEnable_v0(CSL_UART_2_REGS,(UART_INT_LINE_STAT | UART_INT_THR |
            UART_INT_RHR_CTI) );

+ uartIsr code

I could check the UART Interrupt.

        case UART_INTID_RX_THRES_REACH:
            buffer[++bufferIdx] = UART_charGetNonBlocking_v0(CSL_UART_2_REGS);
            UART_charPut_v0(CSL_UART_2_REGS, buffer[bufferIdx]);
            break;