On Thu, 2018-04-05 at 18:32 +0000, Matthew Starr wrote: > > -----Original Message----- > > From: Dan Williams [mailto:[email protected]] > > Sent: Thursday, April 05, 2018 1:22 PM > > To: Matthew Starr; [email protected] > > Subject: Re: u-blox TOBY-R200 Intermittent Long Registration on > > Simple > > Connect > > > > On Tue, 2018-04-03 at 21:19 +0000, Matthew Starr wrote: > > > I have a u-blox TOBY-R200 running on an embedded Linux device > > > with the > > > ModemManager 1.8-rc2 build, plus the patch for "ublox: fix 'any' > > > mode building". On this device there seems to be an issue > > > between the > > > automatic registration of the TOBY-R200 modem and ModemManager > > > reaching the Simple Connect State (5/8) Register. > > > > > > Between reboots I can get ModemManager to have a quick > > > registration > > > and then have a slow (40 or more seconds) registration, where > > > ModemManager seems to have caught the modem right before it > > > finished > > > auto registration or for some reason a denied state occurs and > > > restarts the entire registration over. The issue seems to happen > > > right before simple connect state (5/8) Register is run. > > > > > > Here is what is reported during a quick registration step: > > > Simple connect state (5/8): Register > > > Already registered in network 'XXXXXX', automatic registration > > > not > > > launched... > > > > > > Here is what is reported during a slow registration step: > > > Simple connect state (5/8): Register > > > Launching automatic network registration... > > > > > > See attached files for logs of the fast and slow registration > > > from the > > > start of a simple connect to step (6/8) Bearer > > > > In the quick case, the modem is already registered long before > > SimpleConnect gets to it's registration check. > > > > In the slow case, the modem isn't yet registered. It first reports > > GPRS=denied, UMTS=denied, LTE=idle. MM then starts automatic > > registration on ACM0 and two seconds later gets GPRS=registered on > > ACM1. > > But ACM0 is still blocked running the AT+COPS=0 registration > > command > > which doesn't complete until 30 seconds later. Only then can MM > > continue > > with the connection attempt, even though the modem was registered > > 28 > > seconds before. > > > > So yeah, it's (1) a race with modem firmware between the two cases, > > and > > (2) the modem not returning from the AT+COPS=0 automatic > > registration > > request even when it has already registered. (though there is > > perhaps > > another small race where if the modem has just registered the > > instant > > before MM sends AT+COPS=0 and hasn't yet notified MM, it will then > > do a > > full network scan and registration cycle when the +COPS=0 comes in) > > > > How long has the modem been +CFUN=1 before you send the > > SimpleConnect() request? Can you test whether waiting a couple > > seconds > > after the modem is fully enabled, before sending SimpleConnect(), > > makes a > > difference? > > We could also test-patch MM do that. This isn't a real fix > > though... > > > > Dan > > > > Dan, > > I am using SystemV init scripts for my init this device and I > already tested putting in various sleeps right after starting > ModemManager before I start NetworkManager which is setup to > autoconnect to the cellular connection. I put in a sleep as long as > 30 seconds before NetworkManager is started and the rest of the boot > continues and it made no difference. I was still getting random > results with sometimes MM seeing auto registration had already > completed and other times it forcing a full registration.
Are you enabling the modem from the scripts, or leaving that to NetworkManager? If you're leaving it to NM, you might try "mmcli -m 0 -e" before doing the sleep. Dan > Matt > > > > Any idea on what the difference is between the fast and slow > > > registration and what might be causing it? Any ideas how to fix > > > it? > > > > > > Best regards, > > > Matthew Starr > > > > > > > > > _______________________________________________ > > > ModemManager-devel mailing list > > > [email protected] > > > https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel _______________________________________________ ModemManager-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
