gprs: Block other GSUP procedures during PURGE_MS
GSM 09.02, 19.4.1.4 mandates that no other MAP procedures shall be
started until the PURGE_MS procedure has been completed.
This patch implements this by adding corresponding state and checks
to gprs_subscr_purge, gprs_subscr_location_update, and
gprs_subscr_update_auth_info. If an Update Location or a Send Auth
Info Req procedure is not started because of blocking, the retry
mechanism is aborted to shorten the blocking time. The outstanding
Purge MS procedure itself is not aborted.
Sponsored-by: On-Waves ehf
4 files changed