What I am trying to do is like this. I have an object Quote__c and it has child Quote_Line__c. When I update the currency fields in quote__c it has to update the currency field in the children .So ,in the before update trigger of Quote__c I am trying to update the currency fields in children.But in the Quote__c I have some rollup summary fields. So consequently when the child object get updated it try to update the rollup summary fields in Quote__c(master).As a result it caught in the error
System.DmlException: Update failed. First exception on row 0 with id a0dA0000000rAw4IAE; first error: SELF_REFERENCE_FROM_TRIGGER, Object (id = a0fA0000000ki1a) is currently in trigger ChangeQuoteCurrency, therefore it cannot recursively update itself: 
I tried some methods but I did not get success. I tried This option without any success.