Hi Dan, Il giorno lun 29 set 2025 alle ore 16:57 Dan Williams <[email protected]> ha scritto: > > 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). >
Yes, I confirm that Telit FN990 is supported as an MBIM modem. > 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? > mhi_net is used when the payload is IP or QMAP (added on top of that with kernel module rmnet). MBIM multiplexing is managed by mhi_wwan_mbim only, as far as I know. > 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? > I think that those will use QMI. > > Anyway, review appreciated on that MR. Thanks! > I'll try to have a look at that as soon as possible. Thanks, Daniele > Dan > > (PS: once !1401 lands I'm going to cut a 1.25.995 test release on the > road to 1.26)
