EF designer doesn't see provider

I hav开发者_开发百科e added some ADO.NET EF provider to App.config of project with model (through DbProviderFactories section) and referenced appropriate assembly but EF designer says "Error 175: The specified store provider cannot be found in the configuration, or is not valid". What may be the reasons for that? Does EF designer impose any specific restrictions to providers?

As mentioned in comments I'm almost sure that EF Designer doesn't read providers from configuration file - to have provider available in EF designer you must "install" it and even that is not enough (for example SQL CE 4 is available for EF but it is not available in provider selection in EF designer). Not every provider is available for EF designer and not every provider is available for EF (for example ODBC or OleDB providers are not enabled for EF).