[LS1046] smc_call cannot get the correct result

[linxx]

I'm confused about the smc_call, the regs[1] printed was always ffffffff when running the tfa_get_dram_size() routine cited from u-boot in flexbuild_lsdk2108,

it's also the case when regs0]=SMC_DRAM_BANK_INFO

Is there any precondition ( for CPU or SDRAM) should be mentioned when using smc_call?

phys_size_t tfa_get_dram_size(void)

{

    struct pt_regs regs;

    phys_size_t dram_size = 0;

    regs.regs[0] = SMC_DRAM_BANK_INFO;

    regs.regs[1] = -1;

    smc_call(&regs);

    if (regs.regs[0])

        return 0;

    printf("regs[0]=%x regs[1]=%x\n",regs.regs[0],regs.regs[1]);

    dram_size = regs.regs[1];

    return dram_size;

}