求助：MTK6515M找不到T卡！

GPIO口已经配置好了，开机后一段时间，提示SD card is not ready，不知道怎么回事啊
sd.c中也改了，
static u32 msdc_sd1_power(u32 on, MT65XX_POWER_VOLTAGE powerVolt)
{
#ifdef mtk_EMMC_SUPPORT  // sd1 change to VGP      
    msdc_ldo_power(on, MT65XX_POWER_LDO_VGP, powerVolt, &g_vgp);
#else  // VMC
    //msdc_ldo_power(on, MT65XX_POWER_LDO_VMC, powerVolt, &g_vmc);   
    msdc_ldo_power(on, MT65XX_POWER_LDO_VGP, powerVolt, &g_vgp);
#endif
    msdc_ldo_power(on, MT65XX_POWER_LDO_VMCH, powerVolt, &g_vmch);     
    return 0;     
}