As title. Changing the primary SIM will make mmsDefaultServiceId change. That's the only thing we've done for now. Furthermore, we have to disconnect the on-going MMS connection (if any) under the DSDS scenario, to make sure only one connection is valid at a time.

See more details at bug 945647, comment #11. Quoted from Vicamo: Basically MMS connection is never turned off when "ril.data.defaultServiceId" changes in Gaia because it's actually controlled by "ril.mms.defaultServiceId" instead. Under DSDA configuration, that's fine; but when it comes to DSDS, it's not something we would have expected. Under DSDS, MMS connections should be turned off upon that settingschanged event when we have both 'mms' and 'data' connected no matter they're shared or not. This makes mms-not-disconnected a separated bug, and leaving the patch here becoming really appropriate for the case. Because in my opinion, MmsService should be the only one that knows what "dom.mms.defaultServiceId" really means, while NetworkManager knows all available network interfaces, and ConnectionManager knows the telephony related policies such as DSDA or DSDS that affect the availability of all RILNetworkInterface instances.

Put this bug into backlog.

Firefox OS is not being worked on