SDSI_SIZE_CMD
round_up(packet_size, SDSI_SIZE_CMD));
sdsi_memcpy64_toio(priv->mbox_addr + SDSI_SIZE_CMD, info->payload + 1,
info->size - SDSI_SIZE_CMD);
if (count > (SDSI_SIZE_WRITE_MSG - SDSI_SIZE_CMD))
info.size = round_up(count, SDSI_SIZE_CMD) + SDSI_SIZE_CMD;
info.payload[(info.size - SDSI_SIZE_CMD) / SDSI_SIZE_CMD] = command;