>> I can reliably bring OpenBSD 7.2 to a crawl (and eventually reboot)
>> when plugging a USB3 device into my Raspberry Pi 4B's second USB3
>> port.
>
> I can confirm this happens on my rpi 4B 8gb rev1.5.
> Tested both with the standard image firmware and pftf/rpi4 v1.34.
Heya - thanks for confirming.
>> - Tested RPi's second USB3 port with Raspbian, works flawlessly.
>
> Was that with the exact same hardware combination ?
Yup. Three disks, hooked up via two powered USB hubs:
RPi
|-- USB3.0 port 1
| `-- Powered USB3.0 hub 1
| |-- HDD 1
| `-- HDD 2
`-- USB3.0 port 2
`-- Powered USB3.0 hub 2
`-- HDD 3
> Did you try booting with those two usb3 devices already plugged in ?
> Here it seems only hot plugging triggers that issue and i can have
> both
> my SSD and a keyboard plugged in the two usb3 ports as long as they're
> both already plugged in when power is applied.
Yes, I noticed that as well at one point. Didn't inspire confidence
though, which is why I continued plugging them in after booting to
find out more. (I wanted to use the RPi as a simple NAS and backup, so
I couldn't ignore something wonky like that, despite the workaround.)
> Suggesting that it may be more of a power issue in my specific
> case.
[...]
> Some suggest it's due to power issues, some say it depends on the
> specific hardware. There does not seem to be a consensus.
The interesting thing is that the freeze happens even when the devices
I'm plugging in are *powered* USB hubs. One would assume that this
would prevent too much of a power draw to cause havoc, right? I don't
know, just guessing here. Some USB expert might disagree. But my gut
feeling is that it's not the power. (Also again remembering that it
works absolutely fine under Raspbian.)
Something else I thought about: I can trigger the freeze by plugging
in either a powered USB3 hub or a disk into the 2nd port. Both should
have different power requirements. Also, whatever I'm plugging in is
the *only* connected USB device at that time. Not even keyboard or
mouse, so there's nothing else to draw power. Running disks on each
port directly without any additional power source is definitely going
to cause issues (I've seen that happen), but powered USB hubs should
(and do) remedy that.
I just don't get why all of this works under Raspbian. It really
shouldn't, but it does.
Thanks for those links - the more I read about this the more
mysterious it gets. :)
Cheers,
T
