This patch is just two files (libril-qc-qmi-1.so and libril.so) pulled from the AT&T version (jflteatt) of CM11 (specifically, this version: https://download.cyanogenmod.org/get...2-jflteatt.zip).
I'm overseas right now, so I'm only able to test GSM mode, but it's working just fine for me now. If it's not enough for you, you might want to try the two other changes suggested here: https://jira.cyanogenmod.org/browse/CYAN-2362
To summarize, they are:
- Set telephony.lteOnCdmaDevice=0 in /system/build.prop
- loki_flash the jflteatt CWM with jfltevzw aboot - see here. Note that this is specific to MDK, so don't do this if you're on any other bootloader. Let me know if you want me to create a flashable version of this possible fix.
I didn't need to do either of these things to get it working for me, but you may need to do the first item if you want LTE (I'm currently in a country without LTE, so I can't test).
Flash this for GSM-optimized rils: jfltevzw-gsm-0.2.zip
Flash this to revert to CDMA-optimized rils: jfltevzw-cdma-0.2.zip