Strange issue in Thinkpads T460, T420 during boot

About a month or two ago from now, I started seeing a strange boot "looping" in two different Thinkpads, both equipped with current Slackware.
During boot time, first a kernel loading procedure is usually performed being marked with dots gradually showing up as 3 or 4 lines.
Next, a further boot action should be performed, but often is not - it goes to the starting point before the kernel loading and it goes that way again and again in an endless loop.
Sometimes the boot goes well, sometimes not (about 50-50 %).
The usual solution I use is to press the power button for 2-3 seconds while "looping" to turn the machine off, and then to press it again to turn it on.
That usually makes the incoming boot OK.

Why is that ? Virus, Microcode issue ?

The dots aren't a test; they're the kernel loading. Each dot is a block of code (1 kb? I'm not sure). The bigger the kernel, the more lines of dots. 3-4 lines is normal for a stock kernel. That's usually followed by the message "BIOS data check successful".

yuo might consider to enable the 'compact' option in lilo, and the dots will be much less (and boot becomes faster)

The lenght of "dots" is not important. The problem is that the machine often cannot boot at all without extra off/on power button action.

brodo --

First of all, what hazel and a4z said: you SHOULD be able to boot more quickly if you edit your /etc/lilo.conf file and remove the '#' char at the beginning of unpound this line:

#compact        # faster, but won't work on all systems.

I have a question though, when you boot your Laptop into Slackware is it a cold boot ( shutdown -h ) or a warm boot ( shutdown -r -or- [Ctrl][Alt][Del] -or- maybe starting Slackware after a Windows restart ) ?

I have a problem that sounds a little different from what you describe but I have tracked it down to cold boot -vs- warm boot ...

My Laptop seems to have a BIOS Bug or maybe an ath10k firmware Bug where it occasionally hangs after a warm boot while initializing my ath10k_pci module ( not exactly every-other-time I warm boot but often enough to have noticed the pattern ).

These are the last lines I see on the Console. The system hangs and the only way out is to 'hard boot' ( press and hold the power button to power down ).

[   10.538725] cfg80211: World regulatory domain updated:
[   10.538726] cfg80211:  DFS Master region: unset
[   10.538726] cfg80211:   (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)
[   10.538727] cfg80211:   (2402000 KHz - 2472000 KHz @ 40000 KHz), (N/A, 2000 mBm), (N/A)
[   10.538728] cfg80211:   (2457000 KHz - 2482000 KHz @ 20000 KHz, 92000 KHz AUTO), (N/A, 2000 mBm), (N/A)
[   10.538728] cfg80211:   (2474000 KHz - 2494000 KHz @ 20000 KHz), (N/A, 2000 mBm), (N/A)
[   10.538729] cfg80211:   (5170000 KHz - 5250000 KHz @ 80000 KHz, 160000 KHz AUTO), (N/A, 2000 mBm), (N/A)
[   10.538729] cfg80211:   (5250000 KHz - 5330000 KHz @ 80000 KHz, 160000 KHz AUTO), (N/A, 2000 mBm), (0 s)
[   10.538730] cfg80211:   (5490000 KHz - 5730000 KHz @ 160000 KHz), (N/A, 2000 mBm), (0 s)
[   10.538730] cfg80211:   (5735000 KHz - 5835000 KHz @ 80000 KHz), (N/A, 2000 mBm), (N/A)
[   10.538731] cfg80211:   (57240000 KHz - 63720000 KHz @ 2160000 KHz), (N/A, 0 mBm), (N/A)
[   10.668996] ath10k_pci 0000:3f:00.0: qca6174 hw3.2 (0x05030000, 0x00340aff sub 1a56:1535) fw WLAN.RM.2.0-00180-QCARMSWPZ-1 fwapi 5 bdapi 2 htt-ver 3.26 wmi-op 4 htt-op 3 cal otp max-sta 32 raw 0 hwcrypto 1 features wowlan,ignore-otp,no-4addr-pad
[   10.668997] ath10k_pci 0000:3f:00.0: debug 0 debugfs 1 tracing 0 dfs 0 testmode 0

My Laptop never hangs after a cold boot or a hard boot ( shutdown -h or if I power off with the On/Off Button ).

I am thinking there is a / are register(s) in my hardware that are not clearing on a warm boot.

I've been meaning to research the issue but I only boot Slackware 14.2 on my Laptop and I only reboot when there is a new 4.4.x Kernel and it's not a frequent annoyance for me and there is always something else to do

Anyhow, maybe the cold boot -vs- warm boot phrase might help you find something via google for your specific Laptop ?

HTH

-- kjh

EDIT ...

brodo --

I had to look. This Google Search: linux Thinkpad T460 T420 warm boot hangs

The first hit was this old bug: [Lenovo W520] laptop freezes on ACPI-related actions

Old Bug, Different Model but the T420 is mentioned and the bug persists as of Last Month and the most recent post points at [Lenovo W520] Linux Freezing Issue At Boot

Maybe ???

Here's a fact sheet of this issue:

1. This issue started occuring after one of the current Slackware upgrades in march-april-may of 2017.
I don't remember exactly when, sorry.

2. It happens only when I start the machine using the power button from cold state. No hibernation, etc involved at all.

3. When it happens, a kernel loads itself properly (dots.....) but instead further boot sequence a repeated kernel loading starts again.
So I called it "looping".

4. Using the power button I switch the machine off and on again and then the machine usually boots properly.

5. It does not happen everytime.

6. It happens on 2 different Thinkpads with current Slackware on board : T460 and T420

Hi,
I had a similar problem on a Thinkpad P61 .. turned out to be a memory module that misbehaved when starting from cold.
Once it got a little heat there was no problem. Unfortunately memtest warmed it sufficiently to pass!

If you have any spare modules you might try swapping one out .. or, as I did, remove all the modules except one, try the boot,
rinse and repeat until you can identify the module (if any) that is the troublesome one.

Of course your problem may well NOT be memory so as always YMMV

cheers
pete

pete hilton
saruman@ruvolo-hilton.org

Memory module is not the culpirit IMHO, because here it happened simultaneously on 2 different machines being as always continously updated with current Slackware.

I've just installed fresh new Slackware current into T460.
Playing with current 4.9.41 and older kernels I figured out, that 4.9.38 boots and works OK.
All higher kernels do not boot the machine properly.
I tested it on other machines like T420 with similar yields.

After loading linux "dots", a Bios OK info appears, but after that the following info (I shorted some numbers) is shown:

early console in extract_kernel
input_data: 
input_len:
output:
output_len:
kernel_total_size:

Decompressing Linux...Parsing ELF...done.
Booting the kernel.

And here the action stops, rebooting machine.
Why is that ?

I am typing this on a Lenovo T460 equipped with an Intel Core i5-6200U CPU @ 2.30GHz. I have been running Slackware64-current since I bought this laptop in November 2016 and all kernels have been booting just fine - at the moment it is 4.9.41.
I always use a 'generic' kernel with an initrd image, and the harddisk is fully encrypted using LUKS.
What kernel are you using?

I use smp kernels (vmlinuz-generic-smp-4.9.38-smp, actually).
I also have full LUKS encryption.

I usually use this command when changing kernels:
mkinitrd -c -k 4.9.38-smp -m ext4 -f ext4 -r /dev/cryptvg/root -C /dev/sda2 -L

My uP is Intel Core i5-6300U CPU, similar to yours.
All earlier kernels up to 4.9.38 worked well, as always.

bash-4.4$ lscpu
Architecture:        i686
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              4
On-line CPU(s) list: 0-3
Thread(s) per core:  2
Core(s) per socket:  2
Socket(s):           1
NUMA node(s):        1
Vendor ID:           GenuineIntel
CPU family:          6
Model:               78
Model name:          Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz
Stepping:            3
CPU MHz:             500.030
CPU max MHz:         3000.0000
CPU min MHz:         400.0000
BogoMIPS:            4992.00
Virtualization:      VT-x
L1d cache:           32K
L1i cache:           32K
L2 cache:            256K
L3 cache:            3072K
NUMA node0 CPU(s):   0-3
Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch epb intel_pt tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm mpx rdseed adx smap clflushopt xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp

So you are using a 32bit Slackware. Is there a reason for that? Can you switch to the 64bit variant? The hardware certainly supports it.

I'm somewhat scared by potential compatibility problems with wine and older software in case of a 64-bit version.
I use some of them.
That's why I still use 32-bit Slackware.

Perhaps if you mention that old 32bit software here, people who read the topic may be able to share experiences.