SOLVED: USB seen from one device but not another

Installing and Using OpenWrt
1

I’ve asked about this in the gl.inet forums before but never got any useful help.
On a GL-AR300M16, it can see some USB devices that another can't see (lsusb).
On a MT300N-V2 running 22.03.3 and earlier, it cannot see most devices.

Both have exactly the same packages installed but one simply never sees anything when connecting the device.

I thought it might be a gl.inet problem but maybe it's an openwrt problem.
Since I have no way to know, I thought I'd ask here for help.

How can I diagnose what the problem is? Seems I need some lower level programs than lsmod, lsusb, logread, etc.

2

Are you running gl-inets vendor firmware or official openwrt?

3

Hi, both are running openwrt built using image builder with the same packages.

4

And just to be completely clear -- the openwrt image builder was obtained from openwrt.org -- i.e. the official source, correct?

When you are testing the USB:

  • do you have one device connected at a time, or are multiple devices connected simultaneously?
  • How are they physically connected -- direct USB connection or through a hub? If you are using a hub, is it USB powered or does it have a power brick?
  • Do your USB devices have power bricks or are they USB powered?
  • What types of USB devices are they?
  • What USB device(s) are being detected on one router, but not on the other?
  • What USB device(s) are being detected properly on both routers?
5

Yes, I only use official.

do you have one device connected at a time, or are multiple devices

Only one device is connected.

How are they physically connected -- direct USB connection or through a hub?

No hub, device is connected directly.

Do your USB devices have power bricks or are they USB powered?

USB powered.

What types of USB devices are they?

I've tried a few different ones like two different temp sensors for example.
I'll settle on one and use that one for testing since it can be found on one router but not the other.

What USB device(s) are being detected on one router, but not on the other?
What USB device(s) are being detected properly on both routers?

I'll provide more information on the above tomorrow when I have access to the devices again.

6

Hi,

This has been a problem for years. I’ve asked about it here and in gl.inet forums before.
The devices are currently running openwrt 22.03.3. I only use command line, I do not use GUI.

The problem has something to do with tty to USB between the routers.

The ar300 sees the device and can use it.

$ lsusb
Bus 001 Device 002: ID 0590:00d4 OMRON temp sensor
Bus 001 Device 001: ID 1d6b:0002 Linux 5.10.161 ehci_hcd EHCI Host Controller

The first device is the one I’m trying to get to work on the mango.

The FTDI package and others must be installed for this device to work.
These packages installed on both as the usb sensor needs them;
kmod-usb-serial kmod-usb-serial-ftdi kmod-usb-uhci
I do have usbutils installed.

I also have to run the following commands;
modprobe ftdi_sio # One time
echo 0590 00d4 > /sys/bus/usb-serial/drivers/ftdi_sio/new_id

After doing this, both the ar and the mt300 show the correct result;
$ cat /sys/bus/usb-serial/drivers/ftdi_sio/new_id
0590 00d4

However and this is where the problem lies, when I connect the device to the ar, the correct ttyUSB0 shows up in /dev but it never shows up on the mt.
crw-rw---- 1 root dialout 188, 0 Jan 10 16:06 ttyUSB0

On the mt300, plugging in before powering up, or after power up or rebooting, it never sees it.

In logread, this is all I see, no temp sensor.
usbcore: registered new interface driver ftdi_sio
[ 17.442745] usbserial: USB Serial support registered for FTDI USB Serial Device

$ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux 5.10.161 ehci_hcd EHCI Host Controller

$ lsusb -d 0590:00d4 -v
Gives nothing what so ever.

Nothing in the logread either, nor dmesg.

7

Found the problem. There is a manufacturing issue with the Mango version of the gl.inet. Once I connected a powered USB hub, the device and others all worked at the same time.

Not enough power form the USB port.

8

Is it that or the brick you are using to run the GL-inet?

Because the router should be able to passthrough enough to power, at the least, a thumb drive and if the router is getting low voltage it will have an early death.

Or the hub could have, and probably did, change the address of the thumbdrive.

9

I'm in touch with gl.inet now so I'll update this once I know more.

10

They had no useful answer. This particular model simply doesn't have enough power to handle some devices. That's it.

11

If you decide to buy a powered UB hub look for one that does not pass power back down the male bus.

This would create two power sources to the router.

12

Is this a thing? I’ve never had a powered usb hub reverse power the bus. That would be an exceedingly poor design.

13

Unfortunately, it is.
If you put a USB voltmeter in the middle many are missing a diode that prevents backflow.

I cannot think of any cheaper step than to omit a diode but yeah, its a thing.

By design they must pass power forward, for when they have to power the devices down stream without assistance and that is the same line that can back flow.

14

The problem with that is how, especially the cheap manufacturers, never reveal real specs so you have to take your chances. Amazon is filled with cheap junk that sellers never respond to tech/spec questions about.

15

You can ask the community or search the comments.
If you have a subscription, test it and send it back if it is back feeding.

I should note this is not always bad: if you have a pi zero, you can use the back feed in the USB data port and power the zero that way; one less cord to worry about.

But OP is not talking about a Raspberry Pi, so they should be careful in their choice.

16

The problem is that asking the community on Amazon is pointless. Most people are non technical and think anything that simply works is great so give it good reviews. It's the tech specs that are hard to get, and certainly not from the community. You ask a good question, you get stupid answers.

17

I don't have a magic lasso for Amazon customers.

Although I have seen manufactures answer questions.

Maybe BestBuy is a better choice for you?

18

I'm just sharing my experience. In most cases, if you want tech details from cheap hardware sellers on Amazon, you don't get a response or you get a lot of silly ones from customers. BestBuy doesn't sell stuff like this that I know of and their prices would be much, much higher :).

19

Here is one review that seems to know on a HUB that has sold over 178,000.

Customer Reviews

Underpowered USB Hub with design flaws.
By in the United States on May 6, 2018*Revising my review because what should have fixed it didn't. I still get drop outs copying one flash drive to another on this, which would usually indicate power issues, so I bought a 2amp power adapter for hubs to give it sufficient juice, and still it happens. Something within the device isn't able to handle enough power to make it functional, even when fed from an additional power source.
I don't know if mine is defective or if its simply a design flaw but the button lighting could be better, only the bottom half is lit, and the light guides spill into one another. I've included a photo but its hard to get the exposure just right, but clearly only half of each button lights up, the back half which makes it hard to see.
Do not connect it to an external power source, because its simply spliced into the power line and will backfeed power into your system.
So I have to give it two stars, although it works, it doesn't look like the picture, half the light ring is dark. see less

1 Like
20

Yes, every now and then you'll come across a nicely technical review but they are a bit hard to find.

BTW, this is the hub that I bought.

https://www.amazon.com/gp/product/B0BVBLQZY8/