On Sun, Aug 18, 2019 at 11:07:27AM +1000, Nick wrote: > Hey Reinhard, > > Thanks for the tip! I made some additions, see the patch inline. It now > displays eutran-28 in the mmcli output but whenever I try to use > ???set-allowed-bands with any set of bands I get a page fault.
Hi Nicholas, good catch! I overlooked the active_bands_map[] update (which refers to a different functionality of MM). > > It seems like mm_modem_bands_to_qmi_band_preference() is the likely place to > start digging, but that is just my hunch. > > Debug output: > Sun Aug 18 10:30:29 2019 daemon.debug [12980]: <debug> [1566088229.221066] > Setting new list of bands: 'eutran-1' > Sun Aug 18 10:30:29 2019 kern.info kernel: [ 2850.121024] do_page_fault(): > sending SIGSEGV to ModemManager for invalid write access to 00000000 > Sun Aug 18 10:30:29 2019 kern.info kernel: [ 2850.132164] epc = 77f49afc in > libc.so[77ed8000+92000] > Sun Aug 18 10:30:29 2019 kern.info kernel: [ 2850.137562] ra = 0048cdb5 in > ModemManager[400000+da000] For devices which do not provide feature_extended_lte_band_preference (like Sierra Wireless MC73xx/MC74xx) mm_modem_bands_to_qmi_band_preference() gets called from mm_shared_qmi_set_current_bands() with extended_qmi_lte_bands set to NULL which seems to cause a SIGSEGV in the first memset() within mm_modem_bands_to_qmi_band_preference(). I don't see at the moment how this could happen with the EM7565 you use but I am able to reproduce the segfault with a MC7304 and an unpatched ModemManager 1.10.x version locally with mmcli --set-current-bands. Regards, Reinhard _______________________________________________ ModemManager-devel mailing list ModemManager-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/modemmanager-devel
