On Mon, 2021-11-29 at 10:52 -0500, Peter Naulls wrote: > On 11/26/21 4:52 AM, Aleksander Morgado wrote: > > Hey hey, > > > > This is the second bugfix release in the 1.18.x series, built from > > the mm-1-18 > > branch. > > > > Thanks! > > I've been chasing, as I mentioned a while ago, where "sometimes" the > modem > connection will be brought up as PPP, not qmi. This kind of > connection fails > in our setup for a bunch of reasons, and is not desirable. > > I know that PPP is woven into ModemManager for several reasons, and > building > without is some work - I've seen several prior discussions on this > topic. > > I'm using a custom version of OpenWrt which is approximately the > current > release. I've mitigated the problem somewhat by removing the PPP > connection > scripts (/lib/netif/ppp*), which helps a little. I'm using > ModemManager > 1.18.2 presently, which seems to work pretty well against kernel > 4.14.256. > Some versions of the kernel (perhaps due to timing or whatever) seem > to > trigger the problem more often, although it's hard to confirm that > one > way or another. > > The QMI driver I have is highly customized, and may well be the root > of the > problem - recent kernels seem to have some validation around USB > devices > and whatnot. > > In any case, I tested 1.18.4 today, and 100% of the time the > connection > now comes up in PPP. It's not clear from the changes why this might > now happen - perhaps there's extra validation or something. But I'd > really like to get to the bottom of this - any suggestions in the > current > changes that I should look at?
Do you have debug logs from MM? At the very least MM has to find a netdevice for the modem, otherwise it would fall back to an available AT port for PPP. Does MM find one? Dan
