ghp
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Location: Stuttgart Germany
Contact: Website

Pi B booting with only 3 berry on boot screen sporadically

Fri Sep 17, 2021 10:29 am

Problem, sporadically:
Only 3 raspberry icon are shown when booting (splash screen is off). System boots into desktop, but can't be used (mouse, keyboard not working, ssh access not possible).
Happened in my setup environment in prox 1 of 10 boot sequences and today in school class in two cases on the eight Pi B we are using.

Expected:
Pi B hardware booting, four raspberry icon are shown on boot screen.

Workaround:
Reboot (hard power off, power on) then started the system correctly: 4 icons shown, system is usable. Difficult to explain this workaround to 7th grade kids, when telling them five minutes earlier that a hard shutdown should never be applied.

Software: current 2021-05-07-raspios-buster-armhf-full with apt-get update && apt-get upgrade
Hardware: prox 6 year old Pi B
SD card: 16GB sandisk ultra.

We use these pi b since prox 6 years in school environment. This problem is new. As hardware and power supply are the same and only software is new, I suspect it is a software problem. The SD card are brand new, could also be related to the timing of the cards.

Is this a known problem ? Any solution around ?

Edit: hardware is PI 2 B
Last edited by ghp on Fri Sep 17, 2021 1:55 pm, edited 1 time in total.

Cloudcentric
Posts: 1277
Joined: Fri Sep 14, 2012 9:13 am

Re: Pi B booting with only 3 berry on boot screen sporadically

Fri Sep 17, 2021 1:46 pm

ghp wrote:
Fri Sep 17, 2021 10:29 am
Problem, sporadically:
Only 3 raspberry icon are shown when booting (splash screen is off). System boots into desktop, but can't be used (mouse, keyboard not working, ssh access not possible).
Happened in my setup environment in prox 1 of 10 boot sequences and today in school class in two cases on the eight Pi B we are using.

Expected:
Pi B hardware booting, four raspberry icon are shown on boot screen.

Workaround:
Reboot (hard power off, power on) then started the system correctly: 4 icons shown, system is usable. Difficult to explain this workaround to 7th grade kids, when telling them five minutes earlier that a hard shutdown should never be applied.

Software: current 2021-05-07-raspios-buster-armhf-full with apt-get update && apt-get upgrade
Hardware: prox 6 year old Pi B
SD card: 16GB sandisk ultra.

We use these pi b since prox 6 years in school environment. This problem is new. As hardware and power supply are the same and only software is new, I suspect it is a software problem. The SD card are brand new, could also be related to the timing of the cards.

Is this a known problem ? Any solution around ?

apt-get update && apt-get upgrade

Code: Select all

sudo apt update
sudo apt full-upgrade

https://www.raspberrypi.org/documentati ... #using-apt
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ghp
Posts: 2034
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Location: Stuttgart Germany
Contact: Website

Re: Pi B booting with only 3 berry on boot screen sporadically

Sat Sep 18, 2021 7:47 am

I do not fully understand your comment, I assume that you want to point out that my update/upgrade procedure is wrong which then results to this sporadic failure of the system.

My procedure is:
flash 2021-05-07-raspios-buster-armhf-full , then apt-get update && apt-get upgrade
You propose:
flash 2021-05-07-raspios-buster-armhf-full, then apt update && apt full-upgrade

If any new package release fixes the problem, there should be a remark in the release letter ?

My question was whether the described sporadic problem (booting only with three raspberry icon shown instead of four) is a known problem and whether there is a fix for this.

Cloudcentric
Posts: 1277
Joined: Fri Sep 14, 2012 9:13 am

Re: Pi B booting with only 3 berry on boot screen sporadically

Sat Sep 18, 2021 8:05 am

ghp wrote:
Sat Sep 18, 2021 7:47 am
I do not fully understand your comment, I assume that you want to point out that my update/upgrade procedure is wrong which then results to this sporadic failure of the system.

My procedure is:
flash 2021-05-07-raspios-buster-armhf-full , then apt-get update && apt-get upgrade
You propose:
flash 2021-05-07-raspios-buster-armhf-full, then apt update && apt full-upgrade

If any new package release fixes the problem, there should be a remark in the release letter ?

My question was whether the described sporadic problem (booting only with three raspberry icon shown instead of four) is a known problem and whether there is a fix for this.

With lack of information ie Power Supply & Model / Revision RPi, the only part of your post which I could voluntarily help with was ensuring that full updating of packages and firmware (if applicable).

Sorry to be a nuisance :?
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davidcoton
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Location: Cambridge, UK

Re: Pi B booting with only 3 berry on boot screen sporadically

Sat Sep 18, 2021 9:50 am

ghp wrote:
Sat Sep 18, 2021 7:47 am
My question was whether the described sporadic problem (booting only with three raspberry icon shown instead of four) is a known problem and whether there is a fix for this.
Well, since the first model Pi, known as the Pi B, only had a single CPU, it only displays one Raspberry.
So we do not fully understand your question.
Which model Pi do you really have (it may not matter, but it probably isn't a Pi B).

It is important to get your system correctly up to date before proceeding -- again, it may not matter, but it might just fix something. Please try the advice given, two reasons:
  1. The command you are using does not do exactly the same thing. Use the commands recommended by RPT.
  2. We need to know where we are before trying to diagnose a problem.
No, release notes will not list every problem solved. Only the ones the engineers know they have solved. And then possibly not all the minor changes, which might still be significant.

Now, from your symptoms, three raspberries mean three processors detected. That has been observed, IIRC it was a timing/race condition. The correct upgrade might solve it. If not, it might be a new problem, or it might be a hardware fault. Until your system is up to date, we can't tell.

tl;dr? -- Just use the correct upgrade mantra.
Location: 345th cell on the right of the 210th row of L2 cache

Cloudcentric
Posts: 1277
Joined: Fri Sep 14, 2012 9:13 am

Re: Pi B booting with only 3 berry on boot screen sporadically

Sat Sep 18, 2021 11:33 am

davidcoton wrote:
Sat Sep 18, 2021 9:50 am
ghp wrote:
Sat Sep 18, 2021 7:47 am
My question was whether the described sporadic problem (booting only with three raspberry icon shown instead of four) is a known problem and whether there is a fix for this.
Well, since the first model Pi, known as the Pi B, only had a single CPU, it only displays one Raspberry.
So we do not fully understand your question.
Which model Pi do you really have (it may not matter, but it probably isn't a Pi B).

It is important to get your system correctly up to date before proceeding -- again, it may not matter, but it might just fix something. Please try the advice given, two reasons:
  1. The command you are using does not do exactly the same thing. Use the commands recommended by RPT.
  2. We need to know where we are before trying to diagnose a problem.
No, release notes will not list every problem solved. Only the ones the engineers know they have solved. And then possibly not all the minor changes, which might still be significant.

Now, from your symptoms, three raspberries mean three processors detected. That has been observed, IIRC it was a timing/race condition. The correct upgrade might solve it. If not, it might be a new problem, or it might be a hardware fault. Until your system is up to date, we can't tell.

tl;dr? -- Just use the correct upgrade mantra.


The OP updated post to state six year old 2B so it would be a version 1.1 BCM2836 from February 2015.
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ghp
Posts: 2034
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Location: Stuttgart Germany
Contact: Website

Re: Pi B booting with only 3 berry on boot screen sporadically

Sat Sep 18, 2021 1:43 pm

Hardware info appended below.
Power supply. The wallplug are 5V, 2.1A or more. We use same supply since we use these Pi2B and never had this strange booting problem. I do not see the 'undervoltage flash' while booting.

Extra devices on USB: we use standard usb keyboard and mice, same since 2013 (we upgraded the initial "Pi Model B Rev 2" to "Pi 2 B" in 2015 or so, and also the wallplug power adapters).

In all the cases we observed, a second boot attempt after hard power off succeeded.


cat /proc/device-tree/model

Code: Select all

      Raspberry Pi 2 Model B Rev 1.1
cat /proc/cpuinfo

Code: Select all

processor       : 0
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

processor       : 1
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

processor       : 2
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

processor       : 3
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

Hardware        : BCM2835
Revision        : a01041
Serial          : 000000006289595e
Model           : Raspberry Pi 2 Model B Rev 1.1

PhilE
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Re: Pi B booting with only 3 berry on boot screen sporadically

Mon Sep 20, 2021 10:10 am

This sounds like something first reported in 2020: an ongoing issue with some cores not coming up - usually CPU1. See https://github.com/Hexxeh/rpi-firmware/issues/232 for back story and speculation. I believe this is due to a bug in the Broadcom architecture that only appears when the ARM cache is turned off. Changes to the kernel startup code seem to affect the probability that it occurs, but not with any obvious causality.

PhilE
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Re: Pi B booting with only 3 berry on boot screen sporadically

Mon Sep 20, 2021 11:14 am

That's a long thread - this is the salient comment: https://github.com/Hexxeh/rpi-firmware/ ... -666221012

It's worth noting that the problem seemed to go away after a patch that prevented a critical address on the stack from being aligned to a cache line boundary (or some other relatively large multiple). Now that it's reappeared I'm going to replace that patch with one that loads back the saved value - see https://github.com/raspberrypi/linux/pull/4591.

dom
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Re: Pi B booting with only 3 berry on boot screen sporadically

Mon Sep 20, 2021 4:19 pm

There is a potential fix for this issue in latest rpi-update kernel.
If you have the issue please update and report.

ghp
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Re: Pi B booting with only 3 berry on boot screen sporadically

Mon Sep 20, 2021 8:09 pm

Thank you for the answer.
The SD cards are in school already. Can't update remote; will take till next week to collect the cards, bring them back to the lab, upgrade and redeploy them.
First report end of next week possible.

ghp
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Re: Pi B booting with only 3 berry on boot screen sporadically

Sat Oct 02, 2021 11:05 am

The pi in school are updated. The updated kernel is working, no more failures since.

To summarize the occurrences of the problems:
(lab) raspbian, 1 failure
(lession_1) standard raspbian: 2 failures on 8 pi
(lab) I have booted a pi with updated kernel prox 30 times including power cycle with no problems. Boring procedure.
(lession_2) updated 7 pi to new kernel, left one untouched (standard raspbian): no failures
(lession_3) no failures (7 updated, one standard raspbian)
(lession_4) no failures (7 updated, one standard raspbian)

The good news are that the updated kernel is working. Although the small number of boot sequences does not give a statistical evidence whether problem is solved.

PhilE
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Raspberry Pi Engineer & Forum Moderator
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Location: Cambridge

Re: Pi B booting with only 3 berry on boot screen sporadically

Sat Oct 02, 2021 2:05 pm

I won't be too surprised if you do occasionally lose one core - in my experience it is CPU2, and quite rare - but you should be left with an otherwise working system.

The problem should be solved completely once we move to the next LTS kernel - possibly 5.16, but at this stage it's still a guess.

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