Hi, https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/merge_requests/1407
While debugging the bearer multiplexing and shutdown issue that Daniele Palmas posted MR !1401 for, I found an issue with MHI driver matching. Foxconn T99W175 (Dell 5930e) devices are in MBIM mode driven by mhi- pci-generic. Data ports are exposed by mhi_wwan_mbim, which MM detects as "mhi-pci-generic". I think this applies to other devices too, like Cinterion MV3x, Quectel EM1xx, and Telit FN990 (ie, any device that exposes the IP_HW0_MBIM channel). MM was not detecting this driver and thus not handling lookups from data ports to MBIM control port, and thus not tearing down stale data links on startup like it would with mhi_net or cdc-wdm. A couple questions for those that know more about this... 1) It looks like mhi_net doesn't support multiplexing for MBIM; is that true? 2) How, then, would multiplexing work (if at all?) with MBIM mode on devices like the Sierra EM919x or Qualcomm X24/X55/X65/X75 that expose "MBIM" channels, but only the "IP_HW0" channel that mhi_net binds to? (eg, no IP_HW0_MBIM for mhi_wwan_mbim) Or would we expect these devices to only use QMI? Anyway, review appreciated on that MR. Thanks! Dan (PS: once !1401 lands I'm going to cut a 1.25.995 test release on the road to 1.26)
