rfkill fails to turn on wifi card on Dell Latitude 5490

[Gilbert Fernandes]

Laptop is a Dell Latitude 5490
Was using Windows 10 and installed Ubuntu 20.04
All updates are installed, all firmwares are up to date.

Machine was crashing on sleep : would go into sleep, then waking the machine up would do a full system restart. Edited the file /etc/systemd/sleep.conf to have a line "SuspendState=mem"

The machine now suspends and wakes properly. But... Once the machine comes back from sleep, the wifi card is dead. Rebooting does not fix the issue, only a full shutdown then restart brings the wifi card back.

When doing a tail -f on the /var/log/syslog I can see that rfkill is used to bring the Wifi card back.

Here is what happens when laptop goes into sleep :

Oct 18 09:53:29 alpha systemd[1]: Starting Suspend...
Oct 18 09:53:29 alpha systemd-sleep[3046]: Suspending system...

Oct 18 09:53:29 alpha kernel: [ 136.204296] PM: suspend entry (deep)
Oct 18 09:53:29 alpha systemd[1]: Starting GRUB failed boot detection...
Oct 18 09:53:29 alpha kernel: [ 136.228964] Filesystems sync: 0.024 seconds
Oct 18 09:53:29 alpha systemd[1]: grub-initrd-fallback.service: Succeeded.
Oct 18 09:53:29 alpha systemd[1]: Finished GRUB failed boot detection.
Oct 18 09:55:40 alpha kernel: [ 136.495878] Freezing user space processes ... (elapsed 0.003 seconds) done.
Oct 18 09:55:40 alpha kernel: [ 136.499361] OOM killer disabled.
Oct 18 09:55:40 alpha kernel: [ 136.499363] Freezing remaining freezable tasks ... (elapsed 0.000 seconds) done.
Oct 18 09:55:40 alpha kernel: [ 136.500427] printk: Suspending console(s) (use no_console_suspend to debug)
Oct 18 09:55:40 alpha kernel: [ 136.529343] sd 2:0:0:0: [sda] Synchronizing SCSI cache
Oct 18 09:55:40 alpha kernel: [ 136.534871] sd 2:0:0:0: [sda] Stopping disk
Oct 18 09:55:40 alpha kernel: [ 136.580654] ACPI: EC: interrupt blocked
Oct 18 09:55:40 alpha kernel: [ 136.624750] ACPI: Preparing to enter system sleep state S3
Oct 18 09:55:40 alpha kernel: [ 136.635044] ACPI: EC: event blocked
Oct 18 09:55:40 alpha kernel: [ 136.635046] ACPI: EC: EC stopped
Oct 18 09:55:40 alpha kernel: [ 136.635047] PM: Saving platform NVS memory
Oct 18 09:55:40 alpha kernel: [ 136.635149] Disabling non-boot CPUs ...
Oct 18 09:55:40 alpha kernel: [ 136.636740] smpboot: CPU 1 is now offline
Oct 18 09:55:40 alpha kernel: [ 136.639254] smpboot: CPU 2 is now offline
Oct 18 09:55:40 alpha kernel: [ 136.641610] smpboot: CPU 3 is now offline
Oct 18 09:55:40 alpha kernel: [ 136.643970] smpboot: CPU 4 is now offline
Oct 18 09:55:40 alpha kernel: [ 136.645806] IRQ 122: no longer affine to CPU5
Oct 18 09:55:40 alpha kernel: [ 136.645815] IRQ 128: no longer affine to CPU5
Oct 18 09:55:40 alpha kernel: [ 136.646820] smpboot: CPU 5 is now offline
Oct 18 09:55:40 alpha kernel: [ 136.647982] IRQ 124: no longer affine to CPU6
Oct 18 09:55:40 alpha kernel: [ 136.649021] smpboot: CPU 6 is now offline
Oct 18 09:55:40 alpha kernel: [ 136.650373] IRQ 126: no longer affine to CPU7
Oct 18 09:55:40 alpha kernel: [ 136.650382] IRQ 129: no longer affine to CPU7
Oct 18 09:55:40 alpha kernel: [ 136.651394] smpboot: CPU 7 is now offline
Oct 18 09:55:40 alpha kernel: [ 136.654659] ACPI: Low-level resume complete
Oct 18 09:55:40 alpha kernel: [ 136.654749] ACPI: EC: EC started
Oct 18 09:55:40 alpha kernel: [ 136.654750] PM: Restoring platform NVS memory
Oct 18 09:55:40 alpha kernel: [ 136.655504] Enabling non-boot CPUs ...
Oct 18 09:55:40 alpha kernel: [ 136.655548] x86: Booting SMP configuration:
Oct 18 09:55:40 alpha kernel: [ 136.655549] smpboot: Booting Node 0 Processor 1 APIC 0x2
Oct 18 09:55:40 alpha kernel: [ 136.656533] CPU1 is up
Oct 18 09:55:40 alpha kernel: [ 136.656552] smpboot: Booting Node 0 Processor 2 APIC 0x4
Oct 18 09:55:40 alpha kernel: [ 136.657153] CPU2 is up
Oct 18 09:55:40 alpha kernel: [ 136.657171] smpboot: Booting Node 0 Processor 3 APIC 0x6
Oct 18 09:55:40 alpha kernel: [ 136.657774] CPU3 is up
Oct 18 09:55:40 alpha kernel: [ 136.657792] smpboot: Booting Node 0 Processor 4 APIC 0x1
Oct 18 09:55:40 alpha kernel: [ 136.658525] CPU4 is up
Oct 18 09:55:40 alpha kernel: [ 136.658547] smpboot: Booting Node 0 Processor 5 APIC 0x3
Oct 18 09:55:40 alpha kernel: [ 136.659182] CPU5 is up
Oct 18 09:55:40 alpha kernel: [ 136.659201] smpboot: Booting Node 0 Processor 6 APIC 0x5
Oct 18 09:55:40 alpha kernel: [ 136.659849] CPU6 is up
Oct 18 09:55:40 alpha kernel: [ 136.659868] smpboot: Booting Node 0 Processor 7 APIC 0x7
Oct 18 09:55:40 alpha kernel: [ 136.660511] CPU7 is up
Oct 18 09:55:40 alpha kernel: [ 136.662946] ACPI: Waking up from system sleep state S3
Oct 18 09:55:40 alpha kernel: [ 136.717996] ACPI: EC: interrupt unblocked
Oct 18 09:55:40 alpha kernel: [ 136.801154] ACPI: EC: event unblocked
Oct 18 09:55:40 alpha kernel: [ 136.803505] usb usb1: root hub lost power or was reset
Oct 18 09:55:40 alpha kernel: [ 136.803619] usb usb2: root hub lost power or was reset
Oct 18 09:55:40 alpha kernel: [ 136.803618] iwlwifi 0000:02:00.0: reporting RF_KILL (radio disabled)
Oct 18 09:55:40 alpha kernel: [ 136.803668] sd 2:0:0:0: [sda] Starting disk
Oct 18 09:55:40 alpha kernel: [ 136.804906] iwlwifi 0000:02:00.0: RF_KILL bit toggled to disable radio.

We see the RF_KILL bit is toggled.

When the machine is resumed :

Oct 18 10:00:17 alpha systemd[1]: Starting Load/Save RF Kill Switch Status...
Oct 18 10:00:17 alpha systemd[1]: Started Load/Save RF Kill Switch Status.
Oct 18 10:00:19 alpha kernel: [ 417.390529] Bluetooth: hci0: command 0x0c03 tx timeout
Oct 18 10:00:20 alpha bluetoothd[778]: Endpoint unregistered: sender=:1.72 path=/MediaEndpoint/A2DPSink/sbc
Oct 18 10:00:20 alpha bluetoothd[778]: Endpoint unregistered: sender=:1.72 path=/MediaEndpoint/A2DPSource/sbc
Oct 18 10:00:20 alpha kernel: [ 418.331864] usb 1-7: USB disconnect, device number 4
Oct 18 10:00:20 alpha kernel: [ 418.332086] Bluetooth: hci0: HCI reset during shutdown failed
Oct 18 10:00:20 alpha systemd[1772]: Stopped target Bluetooth.
Oct 18 10:00:20 alpha systemd[1]: Stopped target Bluetooth.
Oct 18 10:00:20 alpha NetworkManager[784]: <info> [1634544020.6595] manager: rfkill: WWAN hardware radio set disabled
Oct 18 10:00:20 alpha NetworkManager[784]: <info> [1634544020.6597] audit: op="radio-control" arg="wwan-enabled" pid=2153 uid=1000 result="success"

At this point, the Wifi card is dead.
If I try to turn it on in console it says the interface cannot do from DOWN to UP because RFKILL bit is set :

gilbert@alpha:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: wlp2s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether d4:3b:04:38:28:b3 brd ff:ff:ff:ff:ff:ff
3: docker0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether 02:42:ae:01:be:41 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 brd 172.17.255.255 scope global docker0
       valid_lft forever preferred_lft forever
gilbert@alpha:~$ sudo ifconfig wlp2s0 up
[sudo] password for gilbert:
SIOCSIFFLAGS: Operation not possible due to RF-kill

Rebooting : wifi card stays disabled.
Turning Off then On : wifi card comes back

I have been able to fix the crash on suspend but I don't know how to have the wifi card come back properly when it comes back from sleep.

The system reports that deep S2 sleep is enabled :

gilbert@alpha:/sys/power/suspend_stats$ cat /sys/power/mem_sleep
s2idle [deep]

If I try to use the Fn + Airplane mode to turn it off, then on again, this happens :

Oct 18 10:00:53 alpha kernel: [ 451.484240] atkbd serio0: Unknown key pressed (translated set 2, code 0x88 on isa0060/serio0).
Oct 18 10:00:53 alpha kernel: [ 451.484256] atkbd serio0: Use 'setkeycodes e008 <keycode>' to make it known.
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 31 with keysym 31 (keycode a).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 32 with keysym 32 (keycode b).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 33 with keysym 33 (keycode c).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 34 with keysym 34 (keycode d).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 35 with keysym 35 (keycode e).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 38 with keysym 38 (keycode 11).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 39 with keysym 39 (keycode 12).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 36 with keysym 36 (keycode f).
Oct 18 10:00:53 alpha gnome-shell[2012]: Window manager warning: Overwriting existing binding of keysym 37 with keysym 37 (keycode 10).
Oct 18 10:00:53 alpha systemd[1]: Starting Load/Save RF Kill Switch Status...
Oct 18 10:00:53 alpha systemd[1]: Started Load/Save RF Kill Switch Status.
Oct 18 10:00:53 alpha NetworkManager[784]: <info> [1634544053.9696] manager: rfkill: WWAN hardware radio set enabled
Oct 18 10:00:53 alpha NetworkManager[784]: <info> [1634544053.9698] audit: op="radio-control" arg="wwan-enabled" pid=2153 uid=1000 result="success"
Oct 18 10:00:54 alpha kernel: [ 451.920779] usb 1-7: new full-speed USB device number 5 using xhci_hcd
Oct 18 10:00:54 alpha kernel: [ 452.070633] usb 1-7: New USB device found, idVendor=8087, idProduct=0a2b, bcdDevice= 0.10
Oct 18 10:00:54 alpha kernel: [ 452.070649] usb 1-7: New USB device strings: Mfr=0, Product=0, SerialNumber=0
Oct 18 10:00:54 alpha kernel: [ 452.073972] Bluetooth: hci0: Bootloader revision 0.0 build 26 week 38 2015
Oct 18 10:00:54 alpha kernel: [ 452.074934] Bluetooth: hci0: Device revision is 16
Oct 18 10:00:54 alpha kernel: [ 452.074943] Bluetooth: hci0: Secure boot is enabled
Oct 18 10:00:54 alpha kernel: [ 452.074947] Bluetooth: hci0: OTP lock is enabled
Oct 18 10:00:54 alpha kernel: [ 452.074950] Bluetooth: hci0: API lock is enabled
Oct 18 10:00:54 alpha kernel: [ 452.074952] Bluetooth: hci0: Debug lock is disabled
Oct 18 10:00:54 alpha kernel: [ 452.074955] Bluetooth: hci0: Minimum firmware build 1 week 10 2014
Oct 18 10:00:54 alpha kernel: [ 452.075411] Bluetooth: hci0: Found device firmware: intel/ibt-12-16.sfi
Oct 18 10:00:54 alpha upowerd[1066]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb1/1-7
Oct 18 10:00:54 alpha systemd[1]: Reached target Bluetooth.
Oct 18 10:00:54 alpha systemd[1772]: Reached target Bluetooth.
Oct 18 10:00:56 alpha kernel: [ 453.868856] Bluetooth: hci0: Waiting for firmware download to complete
Oct 18 10:00:56 alpha kernel: [ 453.869857] Bluetooth: hci0: Firmware loaded in 1754422 usecs
Oct 18 10:00:56 alpha kernel: [ 453.869923] Bluetooth: hci0: Waiting for device to boot
Oct 18 10:00:56 alpha kernel: [ 453.881818] Bluetooth: hci0: Device booted in 11672 usecs
Oct 18 10:00:56 alpha kernel: [ 453.881889] Bluetooth: hci0: Found Intel DDC parameters: intel/ibt-12-16.ddc
Oct 18 10:00:56 alpha kernel: [ 453.884842] Bluetooth: hci0: Applying Intel DDC parameters completed
Oct 18 10:00:56 alpha kernel: [ 453.885878] Bluetooth: hci0: Reading supported features failed (-16)
Oct 18 10:00:56 alpha kernel: [ 453.886853] Bluetooth: hci0: Setting Intel telemetry ddc write event mask failed (-95)
Oct 18 10:00:56 alpha kernel: [ 453.887853] Bluetooth: hci0: Firmware revision 0.1 build 50 week 12 2019
Oct 18 10:00:56 alpha bluetoothd[778]: Endpoint registered: sender=:1.72 path=/MediaEndpoint/A2DPSink/sbc
Oct 18 10:00:56 alpha bluetoothd[778]: Endpoint registered: sender=:1.72 path=/MediaEndpoint/A2DPSource/sbc
Oct 18 10:00:59 alpha systemd[1]: systemd-rfkill.service: Succeeded.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: rfkill 2.34-0.1ubuntu9.1
ProcVersionSignature: Ubuntu 5.11.0-37.41~20.04.2-generic 5.11.22
Uname: Linux 5.11.0-37-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.20
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Mon Oct 18 10:07:02 2021
InstallationDate: Installed on 2021-10-08 (9 days ago)
InstallationMedia: Ubuntu 20.04.3 LTS "Focal Fossa" - Release amd64 (20210819)
SourcePackage: util-linux
UpgradeStatus: No upgrade log present (probably fresh install)

[Gilbert Fernandes (gilbertfernandes-stime)]

tried to use rfkill to bring the wifi card back, fails :

after wake from suspend :

gilbert@alpha:~$ sudo rfkill list
1: dell-wifi: Wireless LAN
 Soft blocked: no
 Hard blocked: no
2: dell-bluetooth: Bluetooth
 Soft blocked: no
 Hard blocked: no
3: phy0: Wireless LAN
 Soft blocked: no
 Hard blocked: yes
4: hci0: Bluetooth
 Soft blocked: no
 Hard blocked: no

trying to turn on :

gilbert@alpha:~$ sudo rfkill unblock 3
gilbert@alpha:~$ sudo rfkill
ID TYPE DEVICE SOFT HARD
 1 wlan dell-wifi unblocked unblocked
 2 bluetooth dell-bluetooth unblocked unblocked
 3 wlan phy0 unblocked blocked
 4 bluetooth hci0 unblocked unblocked

The RF Kill is done on suspend
And it does not work to bring the Wifi card ON when resuming the laptop.

[Gilbert Fernandes (gilbertfernandes-stime)]

Note : it might be a problem in the ilwifi driver. I am not sure.
Perhaps rf-kill does the block properly on suspend
But fails to unblock the card because the ilwifi driver does not bring it back from "hardware lock" to "available" on resume.
So I am not sure of where the problem is, but I tend to think that it's a ilwifi problem :/

https://bugs.launchpad.net/ubuntu/+source/backport-iwlwifi-dkms/+bug/1947561

How can I make sure rfkill does ask properly to the kernel/module to unlock the hardware wifi card, and confirm this is a ilwifi problem ?

[Gilbert Fernandes (gilbertfernandes-stime)]

Found a fix :

Get into Bios (F2 At boot)
Go to : Power Management -> Wireless Radio Control -> Turn everything OFF

This prevents hardware lock of wifi card when going into suspend and undocking from Dell dock.