Re: Usage of WoWLAN with iwlwifi driver (Device phy0 failed to suspend async: error -16)

Am 24.02.2017 um 20:37 schrieb Johannes Berg:

So let's see. The error *isn't* generated by mac80211 or iwlwifi, but
it's still returned through wiphy_suspend(). That function just calls
mac80211 though, and never generates any error conditions by itself. As
a consequence, this must be generated in some callee of wiphy_suspend()
that *isn't* in mac80211/iwlwifi...

__ieee80211_suspend() also doesn't generate any error codes by itself,
let's take a look at iwlmvm's suspend (called through drv_suspend()),
that's iwl_mvm_suspend().

Oh. Can you see if you have CONFIG_IWLWIFI_PCIE_RTPM enabled in your
configuration? If you do, please turn it off and see if that fixes it.

Indeed, you got it! 
I had it on, and turning that off lets me suspend just fine after activating WoWLAN!

See here, the syslog is now clean (I removed the EBUSY-WARNONs for now):
[12383.757181] PM: Syncing filesystems ... done.
[12383.924701] PM: Preparing system for sleep (mem)
[12384.249363] ACPI Warning: \_SB.PCI0.PEG0.DGPU._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20160930/nsarguments-95)
[12385.323377] Freezing user space processes ... (elapsed 0.001 seconds) done.
[12385.325193] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[12385.326602] PM: Suspending system (mem)
[12385.326619] Suspending console(s) (use no_console_suspend to debug)
[12385.326989] sd 5:0:0:0: [sdb] Synchronizing SCSI cache
[12385.327076] sd 0:0:0:0: [sda] Synchronizing SCSI cache
[12385.327199] sd 0:0:0:0: [sda] Stopping disk
[12385.329952] sd 5:0:0:0: [sdb] Stopping disk
[12385.335474] iwlwifi 0000:0a:00.0: L1 Enabled - LTR Enabled
[12385.335737] iwlwifi 0000:0a:00.0: L1 Enabled - LTR Enabled
[12385.426964] ACPI : EC: event blocked
[12385.637708] ACPI Warning: \_SB.PCI0.PEG0.DGPU._DSM: Argument #4 type mismatch - Found [Buffer], ACPI requires [Package] (20160930/nsarguments-95)
[12385.678281] nvidia-modeset: WARNING: GPU:0: Failed to determine which devices were hotplugged: 0x11

[12385.892099] PM: suspend of devices complete after 565.370 msecs
[12385.892586] PM: late suspend of devices complete after 0.484 msecs
[12385.892942] ACPI : EC: interrupt blocked
[12385.893495] ehci-pci 0000:00:1d.0: System wakeup enabled by ACPI
[12385.893568] iwlwifi 0000:0a:00.0: System wakeup enabled by ACPI
[12385.893685] ehci-pci 0000:00:1a.0: System wakeup enabled by ACPI
[12385.893754] xhci_hcd 0000:00:14.0: System wakeup enabled by ACPI
[12385.905567] PM: noirq suspend of devices complete after 12.970 msecs
[12385.905967] ACPI: Preparing to enter system sleep state S3
[12385.906505] ACPI : EC: EC stopped
[12385.906505] PM: Saving platform NVS memory
[12385.906511] Disabling non-boot CPUs ...
[12385.908459] smpboot: CPU 1 is now offline
[12385.919596] smpboot: CPU 2 is now offline
[12385.928100] smpboot: CPU 3 is now offline
[12385.939661] smpboot: CPU 4 is now offline
[12385.952240] smpboot: CPU 5 is now offline
[12385.965252] smpboot: CPU 6 is now offline
[12385.975465] smpboot: CPU 7 is now offline


The problem is that it seems I cannot actually wake the machine anymore afterwards... 
While in the suspend procedure, I see:
[12385.893568] iwlwifi 0000:0a:00.0: System wakeup enabled by ACPI
as expected, I could neither get it to make a tcp connection in tcp-connection mode,
nor could I wake the machine via magic packet in magic-packet mode. 

Could that be some hardware / system firmware limitation, e.g. if my UEFI does not support actually powering
the WiFi hardware if I am in S3? I have yet to (re)check the UEFI config, but since the options are
extremely limited on this Alienware laptop, I guess I will not find anything related to that. 

At least, the suspend problem seems to be clearly related to some path only used if CONFIG_IWLWIFI_PCIE_RTPM is on. 

This still looks fishy in the code though, but let's see if that's the
problem first.

johannes