Re: Dealing with slow USB disks, was: Re: Saving environment variables in u-boot

From: bob prohaska <fbsd_at_www.zefox.net>
Date: Sun, 19 Dec 2021 00:51:34 UTC
On Sun, Dec 19, 2021 at 10:56:04AM +1100, MJ wrote:
> 
> 
> 
> My suggestion: Have you tried directly connecting the USB into the RPI4?
> I've had previous run-ins with RPI3B and powered hubs where it seems to be
> very slow to enumerate the hub and therefore the devices attached.
> 

The same disk and enclosure boot without issue on the Pi4, so I've little
doubt it'd work. 

I tried removing the USB hub and plugging the disk straight into the Pi3,
expecting it to fail on low voltage. To my surprise it warm-booted ok,
but the disk still doesn't enumerate. Five tries at usb reset finally
revealed the disk, run bootcmd_usb0 brought the disk and FreeBSD up
without visible hiccups. The serial console output has been added to
http://www.zefox.net/~fbsd/slow_usb_notes. Five usb resets _isn't_
an improvement, but at least it now seems the trouble isn't the hub.

Thanks for the suggestion!

bob prohaska