Bug report: USB 1 devices through USB 2 hub on USB host port - Sometimes work, sometimes fail!

[porg]

Works fine: USB OTG port <—1— OTGcable <—2— USB2hub <—3— USB1device

With the bootup service "Start USB network on bootup" activated, I dis/re-connected numerous times (~10times) at each juncture (1, 2, 3), and the USB1device always worked fine.

 

 

Works hardly: USB host port <—1— USB2hub <—2— USB1device

The order in which you perform "Enable USB host" + connecting hub + device (at once or consecutively) seems crucial. Sometimes it works not at all. Sometimes it works, and if later (dis/re-)connected in the wrong order/fashion, it won't work at all anymore, until you do a reboot.

 

 

USB is supposed to be easy!

To not get me wrong: USB2 devices such as flash or HD drives work seamlessly on the USB host port. But input devices (USB 1) on the USB host port through a USB 2 hub currently feels like fragile rocket science!

 

[lingenfr]

Levi is correct, I mentally transposed the two examples. I've deleted my post so as to avoid confusion and not start a wifi-like diatribe.

 

[levi]

An easy mistake to make   I'll just leave this here below for reference (and fixed as per Binky's correction, ta)

--

The OTG port puts out a max of 100mA, I thought - which would explain why you can't get away with hooking much up to it.  But porg's talking about the USB host port in that bit of text you (had) quoted, and it's not the first time I've heard that port gets very temperamental should it get the slightest sniff of a non-full speed device.  Although I've also heard that it's the USB chip itself that crashes, and not much that can be fixed with a software patch unfortunately.

 

[Binky]

Shouldn't you be talking about low, full and high speed?

 

[porg]

Shouldn't you be talking about low, full and high speed?

Sorry, if my terminology is not 100% correct. I nevertheless hope that the essence of my report is understood.

I was referring to most input devices as USB1 devices, and most mass storage as USB2 devices.

 

[notaz]

EHCI drivers are of rather poor quality, not much can be done about that with current resources we have.

 

[porg]

EHCI drivers are of rather poor quality, not much can be done about that with current resources we have.

Thanks for that confirmation. So for now better use the USB OTG port for multiple input devices via a hub. Downsides:

- Less stable cable connection: The cable connection gets 1 piece longer (heavier, more traction) on an anyhow smaller port (less friction).

- Slightly more power consumption (with current firmware).

 

[levi]

Well, unless you're using multiple devices which use very small amounts of power or a powered hub you'll come unstuck using the OTG port too.