As you guys would be aware the AmigaOne USB ports are known to be buggy. Be it a hardware or a VIA driver issue they lack auto-detect of devices going in and out, without resistor hacks. A work around was to plug in a hub but as I found out it didn't always work. Which I spoke about in my classic Simple USB easy fix. Well it's been so long since I put it on AmigaWorld here I thought it would be classic by now.

For reference:
http://amigaworld.net/modules/features/index.php?op=r&cat_id=7&rev_id=168&sort_by

I was testing in UBoot. And found UBoot can detect a USB hub and device plugged in when turned on. Together and seperate. And read it. But when an OS such as OS4 or Linux was booted it didn't see any devices at all. This was strange.

But I tested a few other devices as well. I have what I thought was a good hub, a powered hub with a detachable card reader cup that sits on top, but I didn't plug any power in. So I tried with the hub but saw no difference in OS. UBoot could see the hub but it also had a card reader with an SD card it didn't see.

I have a collection of SanDisk sticks so tried those. To my surprise, with only an extension cable connected to the back ports, UBoot detected the stick! I pulled them in and out and it liked those. Then I tested Linux. Then OS4. The SanDisk sticks were detected on the A1 USB ports without any fixes!

Okay I didn't try plugging it directly in the back. It's too hard and my tower has limited space behind it. Can't see a damn thing behind there. But I booted up OS4 and Linux with a SanDisk in. And it could see the stick! I pulled it out. Then put it back in. Twice! It detected it being removed then put in! On the back ports. With no resistor hacks! Just a USB extension cable!


So it looks like an OS just doesn't like some hardware regardless of it working in UBoot. I tried a few sticks and the SanDisk ones were working. And also this Innoster one I tried. Makes a good imposter of that.

So there you go. The on board USB ports can actually work! You can see the lights flashing. How exciting.

Last edited by Hypex on 22-May-2018 at 02:50 PM.

@Hypex

Your UBoot code possibly knows how to enable the terminating resistors, so making it all work without external resistors. Since we never found out how to do it from the VIA docs, OS4 was unable to enable the internal resistors and it only worked properly with external resistors.

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tony

Hyperion Support Forum: http://forum.hyperion-entertainment.biz/index.php

@tonyw

Quote:

Your UBoot code possibly knows how to enable the terminating resistors

I'm not sure what you mean here. I didn't write any UBoot code. Do you mean UBoot itself? In that case if UBoot knows what it is doing is the USB controller then reset again once an OS loads up? And also being the source of UBoot was available, was it handling the USB controller differently, if this was examined?

In any case, regardless of UBoot knowing anything special with the USB ports, as discovered there are USB devices that work simply as they are. In both UBoot and in OS4/Linux. They are detected when plugged in and detected when pulled out. If you have had a working A1 you would be able to check this.

I do wonder what is different with the devices I have. Perhaps they have built in resistance as part of the electronic design that somehow has the effect of the USB ports working, I don't know. I didn't check them with a multi-meter.

@Hypex

I meant in the old faithful U-Boot code. I doubt that the people who used it for the A1 SE/XE boards ever looked at it carefully in that respect.

We know that it is possible to enable/disable the terminations, since PC designs using the VIA 686B were able to do it. However, the docs don't mention it and AFAIK no one ever discovered how to do it. There may be Linux code that one could use, I dunno. It's ancient history these days, since most SE/XE boards were "fixed" by having external resistors soldered on to the back of the board.

The USB "discovery/mount" process depends on the terminating resistors being there, because it measures the voltage on the data lines and thus determines whether something is connected or not.

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cheers
tony

Hyperion Support Forum: http://forum.hyperion-entertainment.biz/index.php

@tonyw

Yes I thought you meant the UBoot code.

Well with the Linux kernels I tested up to the newest Geri compiled none were able to enable any kind of resistors that I noticed. And I confirmed this by testing the back USB ports with devices that don't get detected without hardware work arounds.

The only difference I could see in Linux is that is was able to use the VIA USB2 card I put in a PCI slot. And do USB2 transfers. OS4 could not and always gave errors. So I had to disable EHCI on OS4 until I found an NEC USB2 card and just gave up on the VIA card working with OS4. It was also at this point that I removed my own USB easy fix since I was migrating my front USB ports to the USB2 card.

But as to discovery, some how the Sandisk USB sticks I have tested here, have something inside that enables this process to work. Perhaps it is accidental and triggers something unexpected in the USB port that just happens to activate the electronics needed. I don't know. I just know that to my surprise there are some devices that can be plugged right in and be detected. So wanted to share this with the Amiga world.

@Hypex

Does your extension cable have resistors built into it?

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@billt

Good question. Not that I know of. It's an off the shelf cable, I didn't make it up myself. I should test that. Or pull the tower out again and plug it directly in the back. But I have to remove all the cables above it then try and put them back again. even with a torch it's hard enough.