LaserJet M454dw won't stay in sleep

[mps801]

I have a problem that my new LaserJet M454dw won't stay in sleep mode when not used. The display blanks after the inactivity timeout chosen in the web admin interface, but comes back on in about ten seconds, the fans turn on, mechanics start whirring etc. Then again after the inactivity timeout the display blanks for ten seconds, and the cycle starts over.

Looking at syslog which I'll post below, it seems the printer tries to suspend but aborts due to wakeup source ukernel_pm_driver. What is this, why does it generate a wakeup, and can I somehow prevent this from happening?

There's no setting in the UI that I've been able to discover that would affect this behavior, and the printer has been like this since unboxing and initial setup.

As a semi-workaround I've discovered that if I do something like

(while true; do sleep 60; echo "@PJL ECHO ..."; done) | nc $IP 9100

i.e. open up a connection and keep it alive by periodically sending commands to it (just opening the connection won't work, it will time out and disconnect in five minutes), the printer will be prevented from trying to suspend, but the display will blank and mechanics will stay quiet. This is not a proper solution of course, it's not the actual low-power sleep mode and I cannot always have that command running in the background.

[mps801]

Here's syslog from the printer at debug level. The "MECH: inPowerSave" line at 13:52:30 is basically the same as the one at 13:51:17, the cycle repeats from there (save for some small variations, and random appearance of nginx and dhcp_server messages).

Is there any way I can see kernel messages from before time [87.143]? I also note that the information is not very detailed for debug priority, so I'm not sure if that setting in the UI does anything.

2021-01-12T13:50:16+02:00 hp.local dhcpcd[1283]: eth0: adding route to 10.10.90.0/24
2021-01-12T13:50:16+02:00 hp.local dhcpcd[1283]: eth0: adding default route via 10.10.90.1
2021-01-12T13:50:16+02:00 hp.local dnsmasq[1294]: reading /etc/resolv.conf
2021-01-12T13:50:16+02:00 hp.local dnsmasq[1294]: ignoring nameserver 127.0.0.1 - local interface
2021-01-12T13:50:16+02:00 hp.local dnsmasq[1294]: using nameserver 10.10.10.10#53
2021-01-12T13:50:16+02:00 hp.local /usr/local/bin/samba_mgr[1844]: Info! Stopping samba...#015
2021-01-12T13:50:16+02:00 hp.local dhcpcd[1283]: eth0: removing route to 10.10.90.0/24
2021-01-12T13:50:16+02:00 hp.local /usr/local/bin/samba_mgr[1844]: Info! Stopped samba...#015
2021-01-12T13:50:16+02:00 hp.local /usr/local/bin/samba_mgr[1844]: Info! Starting samba...#015
2021-01-12T13:50:16+02:00 hp.local /usr/local/bin/samba_mgr[1844]: Info! Started samba...#015
2021-01-12T13:50:16+02:00 hp.local ledm_status: MECH: ready
2021-01-12T13:50:16+02:00 hp.local ledm_status: PE: initializing
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.143293] HP_LED_RPC: hp_led_rpc_ioctl().
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.143311] HP_LED_RPC: ERROR: failed in hp_led_rpc_ioctl(), ret=-22
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.150474] HP_LED_RPC: hp_led_rpc_ioctl().
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.151351] HP_LED_RPC: get feedback from led event: led=0x5, state=0, rate=-1
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.151487] HW Power Adapter LibId(2)
2021-01-12T13:51:17+02:00 hp.local ledm_status: MECH: ready
2021-01-12T13:51:17+02:00 hp.local ledm_status: MECH: inPowerSave
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.405658] hpfb_blank mode (1)
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.405682] HPfb: disable clcd
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.405939] HP_LED_RPC: hp_led_rpc_ioctl().
2021-01-12T13:51:17+02:00 hp.local kernel: [ 87.405995] HP_LED_RPC: ERROR: failed in hp_led_rpc_ioctl(), ret=-22
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.032874] PM: Syncing filesystems ... done.
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.042364] PM: Preparing system for sleep (mem)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.042548] Freezing user space processes ... (elapsed 0.011 seconds) done.
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.054431] Freezing remaining freezable tasks ... (elapsed 0.009 seconds) done.
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.064256] PM: Suspending system (mem)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.064261] Suspending console(s) (use no_console_suspend to debug)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.064729] RTC read_time: 100 (01/01/1970 00:01:40), status: 0
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.064909] hpfb_suspend suspend_state (1)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.184250] HP PM: hp_gpio_suspend
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.184346] PM: suspend of devices complete after 119.840 msecs
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.184350] PM: suspend devices took 0.120 seconds
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.184621] PM: late suspend of devices complete after 0.264 msecs
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.185005] PM: noirq suspend of devices complete after 0.374 msecs
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.185010] Disabling non-boot CPUs ...
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.185268] IRQ90 no longer affine to CPU1
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.185291] IRQ142 no longer affine to CPU1
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.185493] CPU1: shutdown
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.185498] hp_cpu_kill: cpu: 0 --> kill cpu:1 config_base (d8809000)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.215168] PM: Wakeup pending, aborting suspend
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.215168] last active wakeup source: ukernel_pm_driver
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.215168] Suspended for 0.212 seconds
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.215176] Enabling non-boot CPUs ...
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.244726] SMP HP: Inside Boot Secondary: prev. scratch2 (88000000) cpu (1) physaddr (88101520)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.244728] Attempting Secondary CPU power on
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.244780] SMP HP: Breaking Secondary with Scratch2 (88000000) at base, Scratch3 (88101520) at sec startup
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.244817] IRQ Affinity: Config_entries(6)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.245309] CPU1 is up
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.245543] PM: noirq resume of devices complete after 0.226 msecs
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.245890] PM: early resume of devices complete after 0.171 msecs
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.246051] HP PM: hp_gpio_resume
2021-01-12T13:51:28+02:00 hp.local kernel: [ 97.246255] hpfb_resume suspend_state (1)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.009536] mmc0: error -110 during resume (card was removed?)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.009615] PM: resume of devices complete after 763.717 msecs
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.009860] PM: resume devices took 0.760 seconds
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.009869] PM: Finishing wakeup.
2021-01-12T13:51:28+02:00 hp.local ledm_status: MECH: inPowerSave
2021-01-12T13:51:28+02:00 hp.local ledm_status: MECH: ready
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.009872] Restarting tasks ... done.
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.023356] hpfb_blank mode (0)
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.023360] HPfb: enable clcd
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.274046] HP_LED_RPC: hp_led_rpc_ioctl().
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.274143] HP_LED_RPC: get feedback from led event: led=0x5, state=1, rate=-1
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.274153] HP_LED_RPC: hp_led_rpc_ioctl().
2021-01-12T13:51:28+02:00 hp.local kernel: [ 98.274157] HP_LED_RPC: ERROR: failed in hp_led_rpc_ioctl(), ret=-22
2021-01-12T13:51:29+02:00 hp.local kernel: [ 99.014547] HW Power Adapter LibId(3)
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: nginx_controller_entry() => waking up from select():ret=(1)
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: nginx_controller_entry()- D-BUS fd is on...
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: _nginx_ctrl_bus_signal_cb Enter: m=(0x00f9ed48), user_data=(0x00000000)
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: Success(DBUS): sd_bus_message_read: events=(0x00050000)
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: _nginx_Ctrl_HandleSecutilEvent Entry
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: Printer is not in service mode
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: sending sigup signal to stop nginx
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: _nginx_Ctrl_HandleSecutilEvent - STOP sent to Nginx
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: _nginx_Ctrl_HandleSecutilEvent - mkdir done
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: sending signal to start nginx
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: _nginx_Ctrl_HandleSecutilEvent - Started Nginx
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: _nginx_Ctrl_HandleSecutilEvent Exit
2021-01-12T13:52:09+02:00 hp.local /usr/local/bin/nginx_ctrl[1320]: _nginx_ctrl_bus_signal_cb Exit
2021-01-12T13:52:30+02:00 hp.local kernel: [ 160.037648] HW Power Adapter LibId(2)
2021-01-12T13:52:30+02:00 hp.local kernel: [ 160.052148] HP_LED_RPC: hp_led_rpc_ioctl().
2021-01-12T13:52:30+02:00 hp.local kernel: [ 160.052167] HP_LED_RPC: ERROR: failed in hp_led_rpc_ioctl(), ret=-22
2021-01-12T13:52:30+02:00 hp.local kernel: [ 160.058524] HP_LED_RPC: hp_led_rpc_ioctl().
2021-01-12T13:52:30+02:00 hp.local kernel: [ 160.058567] HP_LED_RPC: get feedback from led event: led=0x5, state=0, rate=-1
2021-01-12T13:52:30+02:00 hp.local ledm_status: MECH: ready
2021-01-12T13:52:30+02:00 hp.local ledm_status: MECH: inPowerSave

[mps801]

Tried resetting the printer to factory defaults (again) – first thought that fixed the problem, as the printer stayed in sleep for a while, but soon it fell back into the "1 minute on – 10 seconds sleep – 1 minute on – 10 seconds sleep" cycle. Unfortunately I don't have syslog from that, as I hadn't configured it yet after the reset.

Also found that while running my "@PJL ECHO" loop, the printer will lose the ability to accept and print actual print jobs, so that's not even a workaround.

Any thoughts, anyone? Has anyone else seen this? Should I send my printer in for replacement?