Maintaining cache coherency using conditional intervention among multiple master devices is disclosed. In one aspect, a conditional intervention circuit is configured to receive intervention responses from multiple snooping master devices. To select a snooping master device to provide intervention data, the conditional intervention circuit determines how many snooping master devices have a cache line granule size the same as or larger than a requesting master device. If one snooping master device has a same or larger cache line granule size, that snooping master device is selected. If more than one snooping master device has a same or larger cache line granule size, a snooping master device is selected based on an alternate criteria. The intervention responses provided by the unselected snooping master devices are canceled by the conditional intervention circuit, and intervention data from the selected snooping master device is provided to the requesting master device.