TDA4VM: TDA4VM DSI interface configuration issue

Part Number: TDA4VM

Hi, TI support team.

I have a DSI interface problem In ti-processor-sdk-rtos-j721e-evm-08_02_00_05.

The DSI interface could be able to output the signeal with below DSI parameter configuration

(dssDctrlUpdateVideoSizeConfig function in "pdk_jacinto_08_02_00_21/packages/ti/drv/dss/src/drv/dctrl/dss_dctrlDsi.c"

    horzTotal = mInfo->width + mInfo->hFrontPorch + mInfo->hBackPorch + mInfo->hSyncLen;

    dsiObj->videoSizeCfg.vact = mInfo->height;								//[720]
    dsiObj->videoSizeCfg.vfp = 1;									//[1]
    dsiObj->videoSizeCfg.vbp = mInfo->vBackPorch;							//[20]
    dsiObj->videoSizeCfg.vsa = mInfo->vSyncLen;								//[5]
    dsiObj->videoSizeCfg.hsa = (mInfo->hSyncLen * BPP) - 14;						//[106]
    dsiObj->videoSizeCfg.hbp = (mInfo->hBackPorch * BPP) - 12;						//[648]
    dsiObj->videoSizeCfg.rgb = mInfo->width * BPP;							//[3840]
    dsiObj->videoSizeCfg.hfp = (mInfo->hFrontPorch * BPP) - 6;						//[324]
    dsiObj->videoSizeCfg.blkLinePulsePacket = (horzTotal * BPP) - 20 - dsiObj->videoSizeCfg.hsa;	//[4824] ( 1280 + 110 + 220 + 40 ) * BPP - 20 - dsiObj->videoSizeCfg.hsa;

But this configuration is for the FPD Link Serializer to display on the LCD side.

I re-configurate the DSI parameter with standard VESA parameter as blow.

    uint32_t horzTotal;

    horzTotal = mInfo->width + mInfo->hFrontPorch + mInfo->hBackPorch + mInfo->hSyncLen;
    
    dsiObj->videoSizeCfg.vact = 720;
    dsiObj->videoSizeCfg.vfp = 5;
    dsiObj->videoSizeCfg.vbp = 20;
    dsiObj->videoSizeCfg.vsa = 5;
    dsiObj->videoSizeCfg.hsa = (  40 * BPP );
    dsiObj->videoSizeCfg.hbp = ( 220 * BPP );
    dsiObj->videoSizeCfg.rgb = (1280 * BPP );
    dsiObj->videoSizeCfg.hfp = ( 110 * BPP );
    dsiObj->videoSizeCfg.blkLinePulsePacket =  (horzTotal * BPP);

After modification, the DSI interface data lane have no any signal.

Do I miss something for the configuration? 

And how to calculate the "blkLinePulsePacket" value?