What is "CSS operation: data query" wait event in an Oracle StatsPack report?
The note you provided is regarding issues with shutdown: Bug 8299200 - Shutdown immediate hangs (Doc ID 8299200.8). Is it the correct doc you wanted to refer?

Have you recently upgraded to 11.2.0.3?

If so, there's this MOSC note that might be helpful, referring to a bug that causes Clusterware Synchronization Services operations to be very slow, leading to the css-related wait events:

Doc ID 1444483.1