topic Re: Usb hub issues in Tech Help - Software/Hardware etc

Usb hub issues

HairyMcbiker — Thu, 24 Dec 2015 14:51:57 GMT

Anybody come across an issue where a hub works fine on one pc but not another?
I got a new 4 port hub for use with my new pi-zero, but when plugged in via an adapter or an org cable it isn't recognised.
Plug it in to the my pc and it sees it fine.
Pi is powered by a 6A usb charger unit, so no lack of power. I currently have a different hub plugged in with no issues so it isn't the hardware on the pi side.

Re: Usb hub issues

chenks76 — Thu, 24 Dec 2015 15:38:36 GMT

is it a powered usb hub?
i suspect if it isn't then that'll be the problem

Re: Usb hub issues

HairyMcbiker — Thu, 24 Dec 2015 17:21:28 GMT

It's not powered but so what. The other hub (working) isn't powered either.
All that was plugged in as a wifi & keyboard, not like a heavy power draw.
I also tried with nothing plugged in, same issue nothing seen.

Re: Usb hub issues

chenks76 — Thu, 24 Dec 2015 17:44:24 GMT

so what? well it's entirely possible that the hub that doesn't work needs a little bit more juice to work on its own than the other one does.
not all usb hubs are created equally or of equal build quality.

Re: Usb hub issues

HairyMcbiker — Thu, 24 Dec 2015 18:15:59 GMT

Plugging it in via a "charger doctor" shows it taking 9mA with a BT dongle plugged in, with just the BT dongle in the CD it shows 7mA
So not a case of it taking too much power.

Re: Usb hub issues

DaveyH — Thu, 24 Dec 2015 18:52:35 GMT

I have a (powered) Hub that doesn't work with any of my Pis and caused boot loops on one of them but works perfectly fine on my PCs.

Re: Usb hub issues

HairyMcbiker — Thu, 24 Dec 2015 19:05:32 GMT

So must be an issue with the usb interface on pi's then. Verrrrrry stange.

Re: Usb hub issues

7up — Thu, 24 Dec 2015 20:17:09 GMT

I have a mini rii keyboard with touchpad:

Despite seeing many people saying online they can just plug it into their pi and it works instantly... do you think mine ever worked? Absolutely not. I couldn't find anyone else reporting it not working either in order to get it working... so i stopped trying

Re: Usb hub issues

VileReynard — Thu, 24 Dec 2015 20:54:46 GMT

AFAIK A "standard" type B needs 1A at 5V - and is very fussy that the full voltage requirement is met.

Re: Usb hub issues

7up — Thu, 24 Dec 2015 20:56:02 GMT

I thought it was 760mA?
That said.. mine is powered from a 500mA supply so that could explain a thing or two

Re: Usb hub issues

HairyMcbiker — Fri, 25 Dec 2015 11:55:54 GMT

If you read the first post it clearly says I am using a PI ZERO. Something like 180mA needed. I am also powering it from a 6A USB Charger, No lack of power. Yes it can pump 6A down a cable, or 6*1A or any combo, one of the reasons I bought it to replace my many usb chargers. (6 usb ports, capable of supplying up to 6A in total)

Re: Usb hub issues

ejs — Fri, 25 Dec 2015 17:46:00 GMT

You might be able to supply up to 6A to the Pi Zero, but that doesn't mean the Pi Zero can pump 6A out of its USB port. I thought a USB port is normally limited to supplying a maximum of 500mA, and that was part of the USB2 specification, and not just something that could be bypassed by wiring it up to a source that can supply more current. USB devices indicate the maximum amount of power they need, my TP-Link TL-WN822Nv3 that I use with my Pi2, indicates that it uses the full 500mA. I thought the USB controller would add up the total power required by all devices connected to a port, and check if the total could be supplied.
I've got a 7 port USB hub that can work with or without its power supply. However, the hub always indicates that it is self powered, and not bus powered, even when operating without it's own power supply. That is obviously wrong, but I guess it was easier to make it like that than have it report the correct status depending on if its power supply is plugged in or not. It's got a red LED labelled "self power" too, which is on regardless of how the hub is actually being powered. lsusb -v will display a lot of details about USB devices, including how they say they are powered and the max power they claim to need.
Anyway, there's probably some clue as to why it doesn't work in the dmesg output, so you could plug in the hub that doesn't work, then unplug it and plug in whatever you need to read the log messages. Or compare the lsusb -v output of each hub.

Re: Usb hub issues

HairyMcbiker — Sat, 26 Dec 2015 10:27:22 GMT

I wasn't suggesting that the pi would use all 6A I was just saying that there was plenty of power available.
I posted the current used by the hub connected to my pc using a charge doctor. With a bt dongle 9mA with BT dongle direct 7mA so that suggests the hub is taking 2mA.
If I plug all the items into the hub they are recognised by the pc so the hub works.
As has been said must be an issue with Debian on the pi. It is annoying as I bought the hub specifically for the pi.
lsusb on here shows it as:
Bus 006 Device 002: ID 0a05:7211 Unknown Manufacturer hub
which is probably why it isn't recognised on Debian,

Re: Usb hub issues

ejs — Sat, 26 Dec 2015 11:10:18 GMT

The "Unknown Manufacturer" string there makes absolutely no difference to anything else whatsoever. It's just the string retrieved by looking up the numeric IDs in the text file /usr/share/hwdata/usb.ids or wherever it's located in Debian. You could edit the usb.ids file and write in whatever name you like.
Perhaps I didn't explain it clearly enough. What I meant was, no matter how much power you can supply to the Pi, the Pi itself may have its own limit on how much power it can supply from its USB port. Anyway, the problem might not be how much power the devices are actually using, it could be how much power they indicate they need to the computer over the USB protocol.

Re: Usb hub issues

HairyMcbiker — Sat, 26 Dec 2015 15:14:27 GMT

As I said a different hub works fine with the pi, using the same things plugged into it.
The wifi & keyboard neither exceed 100mA draw in total.
It was just this hub that I bought FOR the pi doesn't work and it was the first time I have come across a hub not working on anything. (that supports hubs)

Re: Usb hub issues

ejs — Sat, 26 Dec 2015 16:42:59 GMT

Yes, well, hardware is buggy, especially cheap things like USB hubs. Even if things do basically work OK, like my hub I described, that doesn't mean it works 100% correctly according to how the USB standards say things are supposed to work. My hub is even supposed to be USB Hi-Speed certified, but then I suppose anyone could put that logo on the box.
I still think there's probably some clues as to why it doesn't work in the kernel log messages (readable with dmesg), or comparing the detailed output from lsusb -v might show something.

Re: Usb hub issues

HairyMcbiker — Thu, 31 Dec 2015 12:09:40 GMT

OK plugged in to the pi-zero

Quote
pi@raspberrypi:~ $ lsusb
Bus 001 Device 004: ID 0bda:0179 Realtek Semiconductor Corp.
Bus 001 Device 003: ID 1a40:0101 Terminus Technology Inc. 4-Port HUB
Bus 001 Device 002: ID 1a40:0101 Terminus Technology Inc. 4-Port HUB
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

unplugged

Quote
pi@raspberrypi:~ $ lsusb
Bus 001 Device 004: ID 0bda:0179 Realtek Semiconductor Corp.
Bus 001 Device 003: ID 1a40:0101 Terminus Technology Inc. 4-Port HUB
Bus 001 Device 002: ID 1a40:0101 Terminus Technology Inc. 4-Port HUB
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

So not seen AT ALL. OK it is going through another hub but I need a hub connected to get wifi.
Got another hub today, and it works fine on the zero.

Quote
pi@raspberrypi:~ $ lsusb
Bus 001 Device 004: ID 0bda:0179 Realtek Semiconductor Corp.
Bus 001 Device 010: ID 090c:1000 Silicon Motion, Inc. - Taiwan (formerly Feiya Technology Corp.) Flash Drive
Bus 001 Device 009: ID 05e3:0606 Genesys Logic, Inc. USB 2.0 Hub / D-Link DUB-H4 USB 2.0 Hub

The usb flash drive was plugged in to the hub, plugged into the working hub.
Got a refund of the seller since the hub didn't work on the pi, so am happy with the new hub.