Unfortunatly it's still possible to reproduce the deadlock with this patch...
[ 689.921717] flexcan: probe of 2094000.flexcan failed with error -110
My test setup:
PC with CAN-USB dongle connected to can0 and can1.
PC:
$ while true; do cansend can0 '123#DEADBEEF'; done
iMX6ull:
root@iwg26:~# systemctl suspend
[ 365.858054] systemd[1]: Reached target Sleep.
root@iwg26:~# [ 365.939826] systemd[1]: Starting Suspend...
[ 366.115839] systemd-sleep[248]: Suspending system...
[ 366.517949] dpm_run_callback(): platform_pm_suspend+0x0/0x5c returns
-110 [ 366.518249] PM: Device 2094000.flexcan failed to suspend: error -110
[ 366.518406] PM: Some devices failed to suspend, or early wake event
detected [ 366.732162] dpm_run_callback():
platform_pm_suspend+0x0/0x5c returns -110 [ 366.732285] PM: Device
2090000.flexcan failed to suspend: error -110 [ 366.732330] PM: Some
devices failed to suspend, or early wake event detected [ 366.890637]
systemd-sleep[248]: System resumed.
CAN1, CAN0 suspended failed, then CAN0, CAN1 resumed back, so CAN0/CAN1 can work fine.
[ 366.923062] systemd[1]: Started Suspend.
[ 366.942819] systemd[1]: sleep.target: Unit not needed anymore. Stopping.
[ 366.954791] systemd[1]: Stopped target Sleep.
[ 366.962402] systemd[1]: Reached target Suspend.
[ 366.977546] systemd-logind[135]: Operation 'sleep' finished.
[ 366.979194] systemd[1]: suspend.target: Unit not needed anymore.
Stopping.
[ 366.993831] systemd[1]: Stopped target Suspend.
[ 367.139972] systemd-networkd[220]: usb0: Lost carrier [ 367.294077]
systemd-networkd[220]: usb0: Gained carrier
root@iwg26:~# candump can0 | head -n 2
can0 123 [4] DE AD BE EF
can0 123 [4] DE AD BE EF
root@iwg26:~# candump can1 | head -n 2
can1 123 [4] DE AD BE EF
can1 123 [4] DE AD BE EF
root@iwg26:~# systemctl suspend
root@iwg26:~# [ 385.106658] systemd[1]: Reached target Sleep.
[ 385.147602] systemd[1]: Starting Suspend...
[ 385.246421] systemd-sleep[260]: Suspending system...
[ 385.634733] dpm_run_callback(): platform_pm_suspend+0x0/0x5c returns
-110 [ 385.634855] PM: Device 2090000.flexcan failed to suspend: error -110
[ 385.634897] PM: Some devices failed to suspend, or early wake event
detected [ 385.856251] PM: noirq suspend of devices failed [ 385.998364]
systemd-sleep[260]: System resumed.
CAN0 suspended failed, CAN1 noirq suspended failed, then CAN1, CAN0 resumed back, so CAN0/CAN1 can work fine.
[ 386.023390] systemd[1]: Started Suspend.
[ 386.031570] systemd[1]: sleep.target: Unit not needed anymore. Stopping.
[ 386.055886] systemd[1]: Stopped target Sleep.
[ 386.061430] systemd[1]: Reached target Suspend.
[ 386.066142] systemd[1]: suspend.target: Unit not needed anymore.
Stopping.
[ 386.112575] systemd-networkd[220]: usb0: Lost carrier [ 386.116797]
systemd-logind[135]: Operation 'sleep' finished.
[ 386.146161] systemd[1]: Stopped target Suspend.
[ 386.260866] systemd-networkd[220]: usb0: Gained carrier root@iwg26:~#
candump can0 | head -n 2
can0 123 [4] DE AD BE EF
can0 123 [4] DE AD BE EF
root@iwg26:~# candump can1 | head -n 2
can1 123 [4] DE AD BE EF
can1 123 [4] DE AD BE EF
root@iwg26:~# systemctl suspend
[ 396.919303] systemd[1]: Reached target Sleep.
root@iwg26:~# [ 396.964722] systemd[1]: Starting Suspend...
[ 397.067336] systemd-sleep[268]: Suspending system...
[ 397.574571] PM: noirq suspend of devices failed [ 397.834731] PM: noirq
suspend of devices failed [ 397.807996] systemd-networkd[220]: usb0: Lost
carrier [ 398.156295] dpm_run_callback(): platform_pm_suspend+0x0/0x5c
returns -110 [ 398.156339] PM: Device 2094000.flexcan failed to suspend:
error -110 [ 398.156509] PM: Some devices failed to suspend, or early wake
event detected [ 398.053555] systemd-sleep[268]: Failed to write
/sys/power/state:
Device or resource busy
But the log here is very strange and chaotic, it looks like CAN0 suspended failed, then resumed back, so CAN0 can work fine.
CAN1 noirq suspend failed, but have not resumed back, so CAN1 still in stop mode, cannot work. I think this may be other device noirq suspend failed
broke the resume of CAN1.
Could you do more debug to help locate the issue?
[ 398.074751] systemd[1]: systemd-suspend.service: Main process exited,
code=exited, status=1/FAILURE [ 398.076779] systemd[1]:
systemd-suspend.service: Failed with result 'exit-code'.
[ 398.109255] systemd[1]: Failed to start Suspend.
[ 398.118704] systemd[1]: Dependency failed for Suspend.
[ 398.136283] systemd-logind[135]: Operation 'sleep' finished.
[ 398.137770] systemd[1]: suspend.target: Job suspend.target/start failed
with result 'dependency'.
[ 398.139105] systemd[1]: sleep.target: Unit not needed anymore. Stopping.
[ 398.167590] systemd[1]: Stopped target Sleep.
[ 398.201558] systemd-networkd[220]: usb0: Gained carrier
Log here also strange.
Best Regards,
Joakim Zhang
root@iwg26:~# candump can0 | head -n 2
can0 123 [4] DE AD BE EF
can0 123 [4] DE AD BE EF
root@iwg26:~# candump can1 | head -n 2
nothing on can1 anymore :-(
root@iwg26:~# rmmod flexcan
[ 622.884746] systemd-networkd[220]: can1: Lost carrier [ 623.046766]
systemd-networkd[220]: can0: Lost carrier root@iwg26:~# insmod
/mnt/flexcan.ko [ 628.323981] flexcan 2094000.flexcan: registering netdev
failed
and can1 fails to register with:
[ 628.347485] flexcan: probe of 2094000.flexcan failed with error -110
/Sean
I have added some more debug, same test setup:
https://gist.github.com/sknsean/81208714de23aa3639d3e31dccb2f3e0
root@iwg26:~# systemctl suspend
...
https://gist.github.com/sknsean/2a786f1543305056d4de03d387872403
/Sean
