ULPM doesn't work with MCU version 002.011 for wp77xx

[akankshaashwini]

Tested with pmtool on a Mangoh red with wp77xx module.

pmtool bootOn timer 60
SUCCESS!
pmtool shutdown
Initiated the MDM shutdown
Doesn't perform a shutdown

[CoRfr]

Which version of Legato did you test? Also which Linux

[akankshaashwini]

I tested with legato 19.04 version. Linux 3.18. Toolchain SWI9X06Y_02.22.12.00.
I used Release 11 resources just with an updated legato version to 19.04:
https://source.sierrawireless.com/resources/airprime/software/wp77xx/wp77xx-firmware-latest-release-components/

[jvermillard]

if you have the legato devMode app, I don't know why, but it's preventing ULPM to shutdown the module. Try to remove it.

[akankshaashwini]

I don't find the devMode app installed.

[CoRfr]

Yes the devMode app keeps the target alive. See https://docs.legato.io/latest/basicTargetDevMode.html:

• holds a wake lock, so the target won't go to sleep when disconnected from USB.

I created an internal tracker, LE-13385, will keep you posted.

[Redferne]

Can confirm this problem with the same setup (WP7702), also tried Legato 19.05. However it seems that PSM can still be triggered by using the psm_test command and the system powers down.
Edit: Found something! If PSM is enabled then pmtool shutdown does not work.
So it's possible to disable PSM in the modem by using:

root@swi-mdm9x28-wp:~# microcom /dev/ttyAT
at+cpsms=0
OK

Exit microcom by CTRL+a and then CTRL+x
Now pmtool shutdown successfully shuts down the board.

Can also report that kernel autosleep is not working when legato is running (maybe this is intended?) Is there a workaround?

root@swi-mdm9x28-wp:~# cat /sys/kernel/debug/wakeup_sources |sed -e s/"^       "/"unnamed"/ | awk '{print $6 "\t" $1 "\t" $2 "\t" $3 "\t" $4 "\t" $5 "\t" $7 "\t" $8 "\t" $9 "\t" $10}' | grep -v "^0"

active_since	name	active_count	event_count	wakeup_count	expire_count	total_time	max_time	last_change	prevent_suspend_time
2130053	[eventfd]	1	1	0	0	2130053	2130053	1252296	0

I'm connected to the console UART port (not CF3 USB) and devMode is not enabled.

[auandrew]

I cannot reproduce this issue with all the exact same versions.

root@swi-mdm9x28-wp:~# microcom /dev/ttyAT

ati8
Legato Ver: 19.04.0_a62fc5efed553c95ae8e2af417420976
Yocto Ver: SWI9X06Y_02.22.12.00 2019-04-24_20:46:59
OS Ver: Linux version 3.18.44 (jenkins@jenkins) (gcc version 6.2.0 (GCC) ) #2 PREEMPT Wed Apr 24 20:48:03 UTC 2019
LK Ver: SWI9X06Y_02.16.02.00
RootFS Ver: SWI9X06Y_02.22.12.00 2019-04-24_20:46:59
UserFS Ver: unknown
MCU Ver: 002.011

In general, any active wake lock would prevent Legato's ULPM from proceeding with a shutdown, e.g.

Jan 6 01:23:16 swi-mdm9x28-wp user.info Legato: INFO | powerManagerService[2899]/powerMgr T=main | le_pm.c OnClientConnect() 270 | Connection from client pmtool/3195
Jan 6 01:23:16 swi-mdm9x28-wp user.err Legato: =ERR= | powerManagerService[2899]/powerMgr T=main | le_ulpm.c le_ulpm_ShutDown() 499 | Wakelock held!! System can't be shut down. Try again.
Jan 6 01:23:16 swi-mdm9x28-wp user.info Legato: INFO | powerManagerService[2899]/powerMgr T=main | le_pm.c OnClientDisconnect() 298 | Client pid 3195 disconnected.

Thus, in your environment where the issue manifests, is there any other active wake, just like devMode but not devMode itself?

There is related documentation about wake locks at

• https://docs.legato.io/latest/conceptsPwrMgmt.html

and pmtool at

• https://docs.legato.io/latest/toolsTarget_pmTool.html.