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Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 2:02 am
by Nilpo
I've purchased two different Raspberry Pi 3 B+ now and neither one of them came with anti-static protection.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 3:43 am
by horgh
I just started running memtester after rebooting with the new settings.

My Pi was still stable at over 3 days of uptime. Here's what vcgencmd said before I rebooted:

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# vcgencmd get_config int | grep -E "(volt|sdram)"
over_voltage_avs=0x10c8e
over_voltage_avs_boost=0x2ab98
sdram_freq=450

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 8:02 am
by PhilE
@Nilpo That's a good point. You are correct that they come without anti-static bags, but the box is made is made of cardboard with an anti-static coating. We should have made that clear on the packaging.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 8:17 am
by PhilE
@evizw2 and @horgh - your output rules out your 3B+s as being extreme in terms of silicon speeds (either fast or slow).

We are due to get a failing board back soon, which hopefully will allow us to root-cause the problem, but I'd still like a few more examples - particularly from the UK where shipping is quick.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 10:18 am
by PeterO
I've been running memtest with 1400/450 for an hour or so with no problems
When I upped it to 1400/500 is locked up within a minute !
And it wouldn't reboot !
I tried a power cycle three times, then took the USB HD and put it on my Desktop machine and edited config.txt back to 1400/450 and now it has booted again.

PeterO

Values at 450Mhz
over_voltage_avs=0x124f8
over_voltage_avs_boost=0x2ab98
sdram_freq=450


Values at 500Mhz
over_voltage_avs=0x155cc
over_voltage_avs_boost=0x2f4d6
over_voltage_sdram_p=2
sdram_freq=500
sdram_schmoo=0x2000020

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 2:29 pm
by evizw2
I spoke too soon about using just sdram_freq=450, as it rebooted overnight. Nothing showed up on the serial console indicating a crash. I'll try running with arm_freq=1200 to see if it reboots over the next few days. I suppose this overnight reboot could also be a different problem.

I don't mind sending in my 3B+, but I'm also located in Canada.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 2:37 pm
by PhilE
We have a returned board on the bench now - thank you, PeterO - and it is failing for us. Allow us some time to run tests, then I'll post an update.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 4:40 pm
by PeterO
PhilE wrote:
Tue Apr 10, 2018 2:37 pm
We have a returned board on the bench now - thank you, PeterO - and it is failing for us. Allow us some time to run tests, then I'll post an update.
It's good to know the trip to Cambridge was worth it :-) But really it was just an excuse to go out for a nice ride on my motorbike :lol:
PeterO

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 6:35 pm
by dom
So, can anyone with unreliability try running memtester as requested by Phil.

If you get failures (it normally detects sdram problems pretty quickly (I'd say an hour is more than enough),
then try again with sdram_freq=450. Hopefully that will pass.

If it does pass can you try again with:

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sdram_schmoo=0x01000010
added to config.txt (leave sdram_freq at default).

Let me know if that makes memtester more reliable.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 7:44 pm
by evizw2
Unfortunately in my case, with sdram_freq=450, memtester 512M crashes in well under an hour.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 7:49 pm
by PhilE
It's worth trying with the sdram_schmoo setting as well as, and if that works, without the sdram_freq=450.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 8:38 pm
by ejolson
PhilE wrote:
Tue Apr 10, 2018 7:49 pm
It's worth trying with the sdram_schmoo setting as well as, and if that works, without the sdram_freq=450.
Is there any way for educational purposes of providing more details what the schmoo flags do?

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 8:47 pm
by jamesh
ejolson wrote:
Tue Apr 10, 2018 8:38 pm
PhilE wrote:
Tue Apr 10, 2018 7:49 pm
It's worth trying with the sdram_schmoo setting as well as, and if that works, without the sdram_freq=450.
Is there any way for educational purposes of providing more details what the schmoo flags do?
I think I speak for most people when I say "I have no idea"

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 8:51 pm
by PhilE
I don't know the specifics, but the purpose is to configure the SDRAM PHY delay lines.

Re: Raspberry Pi 3 B+ lockups

Posted: Tue Apr 10, 2018 8:51 pm
by evizw2
With both sdram_freq=450 and sdram_schmoo=0x01000010 it took 11 minutes before my board rebooted while running memtester.

Edit: Without sdram_schmoo modification, but with sdram_freq=450 and arm_freq=1200, memtester has been going for two hours now without a reboot.

Edit 2: With just arm_freq=1200 it's been up for 2 hours of memtester without a reboot.

Edit 3: Same result with arm_freq=1300 for a little under 2 hours. I'm going to leave it running overnight at 1350.

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 4:22 am
by horgh
Great news that you have a Pi with the symptoms! Thanks for your efforts & for letting us know!

I've been running

Code: Select all

memtester 512M
for about 24 hours and it's been stable. Settings:

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over_voltage_sdram_p=4
over_voltage_sdram_i=4
It sounds like 24 hours is much more than necessary, but anyway!

I'm going to try changing the above settings to 3 and 4 respectively and repeat.

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 6:55 am
by bensimmo
jamesh wrote:
Tue Apr 10, 2018 8:47 pm
ejolson wrote:
Tue Apr 10, 2018 8:38 pm
PhilE wrote:
Tue Apr 10, 2018 7:49 pm
It's worth trying with the sdram_schmoo setting as well as, and if that works, without the sdram_freq=450.
Is there any way for educational purposes of providing more details what the schmoo flags do?
I think I speak for most people when I say "I have no idea"
Any chance a misspelling of shmoo ?

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 8:01 am
by PeterO
bensimmo wrote:
Wed Apr 11, 2018 6:55 am
Any chance a misspelling of shmoo ?
No. If you run the vcgencmd command given above you get this output

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Values at 500Mhz
over_voltage_avs=0x155cc
over_voltage_avs_boost=0x2f4d6
over_voltage_sdram_p=2
sdram_freq=500
sdram_schmoo=0x2000020
PeterO

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 8:06 am
by PhilE
I think what bensimmo means is that our choice of variable name is a misspelling of sdram_shmoo (as in "shmoo plot"), and he's probably right.

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 8:20 am
by PeterO
PhilE wrote:
Wed Apr 11, 2018 8:06 am
I think what bensimmo means is that our choice of variable name is a misspelling of sdram_shmoo (as in "shmoo plot"), and he's probably right.
Sorry, never heard of a "shmoo plot" before.
PeterO

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 2:35 pm
by evizw2
I ended up trying arm_freq=1375 overnight, which crashed 15 minutes after I left it. I also tried with just sdram_schmoo=0x01000010 this morning and it only ran for 10 minutes. I'm going to try ratcheting down arm_freq in increments of 25 until I find one where it consistently works.

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 3:37 pm
by GeekonaBike
Not sure if anyone has mentioned this, but switching from a 1amp to a 2amp micro usb power supply solved my crashing issues,

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 3:50 pm
by jamesh
GeekonaBike wrote:
Wed Apr 11, 2018 3:37 pm
Not sure if anyone has mentioned this, but switching from a 1amp to a 2amp micro usb power supply solved my crashing issues,
1A will be woefully underpowering the PI3B+ - it does require at least 2A.

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 4:06 pm
by evizw2
I'm using the 2.5A from CanaKit that came with the 3B+. So far memtester has been running for just over 2 hours at arm_freq=1350 without a crash.

Re: Raspberry Pi 3 B+ lockups

Posted: Wed Apr 11, 2018 4:48 pm
by PhilE
1A will be woefully underpowering the PI3B+ - it does require at least 2A.
Our recommendation is to get a 2.5A supply and to avoid (or at least check) inline switches that can cause voltage drops.