How to get and set device buffer size for Mellanox ConnectX-3 InfiniBand devices with mlx4 and ib_ipoib driver?

Issue

• How to get and set device buffer size for Mellanox ConnectX-3 InfiniBand devices with mlx4 and ib_ipoib driver?
• We are not able to set / or get any ring buffer value for InfiniBand interface
• We are seeing some performance related issue and need to increase rx ring size

# ethtool -g ib0
Ring parameters for ib0:
Cannot get device ring settings: Operation not supported

• When we use drivers provided by Mellanox - we are able to get the values:

# ethtool -g ib0
Ring parameters for ib0:
Pre-set maximums:
RX:             8192
TX:             8192
Current hardware settings:
RX:             2048
TX:             2048