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

On Sun, Dec 19, 2021 at 01:13:12PM -0800, Mark Millard wrote:
> On 2021-Dec-19, at 11:28, bob prohaska <fbsd at www.zefox.net> wrote:
> 
> > On Sun, Dec 19, 2021 at 12:55:12AM -0800, Mark Millard wrote:
....
> >> (The above are JMicro based.) Can you identify your adapter
> >> type?
> >> 
> > 
> > The enclosure is simply marked SABRENT EC_UASP, 
> > The usb-sata bridge is marked   JMS576
> >                                2026 QH8A3A A
> >                                E76H20013
> 
> THat is one of the ones listed on
> 
> https://jamesachambers.com/fixing-storage-adapters-for-raspberry-pi-via-firmware-updates/
> 
> as potentially fixable (with quirks possibly involved). See:
> 
> https://www.sabrent.com/download/jmicron-sabrent-update-tool/
> 
> for SABRENT's Firmware-Update Tool. Looks like Windows7+ is
> a required context for doing the firmware update.
>
Yes, I'm searching for  a Windows machine to give it a try.
I wonder how new the update is; running strings on the .exe finds
Borland C++ - Copyright 2002 Borland Corporation
 
> I've not checked if FreeBSD has any quirks in place.
> 
My troublesome Pi3 and trouble-free Pi4 with JMicron bridge report
umass0:  SCSI over Bulk-Only; quirks = 0x8100
da0: quirks=0x2<NO_6_BYTE>

A second  Pi3 that uses the same Seagate drive through 
an ASMT bridge reports
umass0:  SCSI over Bulk-Only; quirks = 0x0100
da0: quirks=0x2<NO_6_BYTE>
It has no trouble finding the disk in repeated attempts.

> 
> The power (current) requirements to get this drive spinning is double
> what a USB2 port has for a maximum in the USB2 standard: The drive is
> problematical unless power is being drawn from 2 USB2 ports for
> the one drive. EC-UASP does not seem to support such
> dual-USB2-port use. (The RPi*'s are not designed to provide extra
> power on a USB2 port as far as I know.)
>

It's clear that I'm pushing limits quite hard at startup. Still, by
the time of disk discovery the initial surge is over. There's no
mouse or keyboard on either Pi3. The Pi3 that finds the disk is 
running -current, the Pi3 that can't find the disk is stable/13.
 
> That things do not work well for USB2 port use is not surprising.
> 
> The startup current requirement is nearly as large as the total
> current for USB on the RPi*'s. (The RPi*'s support less of a total
> than the sum of the individual ports maximums: only 1200mA total.)

I'm _just_ under the limit at spinup, but well under once running.

> 
> SSD's are a better match to RPi* power than spinning rust is, unless
> the spinning rust has its own power supply and is already powered
> before the RPi* is powered. There are types of cases that have such
> independent power instead of being bus-powered. Bus-powered spinning
> rust is a problem for single-port USB2 (and possibly even single-port
> USB3).
>

I don't plan to run the disk without an auxiliary power supply 
long term. In fact, since removing the powered hub doesn't 
seem to help with the enumeration problem it could be put back.

Thanks for writing!

bob prohaska