MC74xx: only one QMI port works after firmware preference

Hey,

Working with a MC7455 with rmnet0 and rmnet1 enabled (AT!USBCOMP=1,1,50D).

It looks like if a firmware preference update is done (i.e. “DMS Set Firmware Preference” to select a different modem+pri image pair), when the module reboots after the preference setting, only one of the QMI ports end up responding, the one that is used first.

I’ve validated this with the qmi_wwan kernel driver and qmicli userspace utility. E.g.:

$ sudo qmicli -d /dev/cdc-wdm0 --dms-list-stored-images
(returns list of images)
$ sudo qmicli -d /dev/cdc-wdm0 --dms-select-stored-image="modem1,pri4"
$ sudo qmicli -d /dev/cdc-wdm0 --dms-set-operating-mode=offline
$ sudo qmicli -d /dev/cdc-wdm0 --dms-set-operating-mode=reset
(wait for reboot...)
$ sudo qmicli -d /dev/cdc-wdm0 --dms-list-stored-images
(first time tried, times out)
$ sudo qmicli -d /dev/cdc-wdm0 --dms-list-stored-images
(returns list of images)
$ sudo qmicli -d /dev/cdc-wdm1 --dms-list-stored-images
(the alternate cdc-wdm1 always times out)

If I try to use cdc-wdm1 instead after the reboot, cdc-wdm1 will end up working and cdc-wdm0 won’t work. i.e. only the first cdc-wdm port used after the firmware preference selection works. This issue only happens during the first boot after the running image update.

If I proceed to power cycle again, both cdc-wdm devices will work correctly:

$ sudo qmicli -d /dev/cdc-wdm0 --dms-set-operating-mode=offline
$ sudo qmicli -d /dev/cdc-wdm0 --dms-set-operating-mode=reset
(wait for reboot...)
$ sudo qmicli -d /dev/cdc-wdm0 --dms-list-stored-images
(returns list of images)
$ sudo qmicli -d /dev/cdc-wdm1 --dms-list-stored-images
(returns list of images)

Can anyone from Sierra acknowledge this issue? Thanks!

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