Arch Linux

denisfalqueto

Member

From: ES, Brazil

Registered: 2006-03-24

Posts: 197

[Found cause] Midi-usb cable and usb modules loading

Hello,

I've bought a (el cheapo) midi-usb cable so I can play my musical keyboard (also el cheapo... but I'm no professional ). The thing is that when I try to use it in my laptop (Gigabyte W566U, Arch 64 bits, up to date), it is not reliable. I play the keys and the midi events are not delivered correctly. I'm using aseqdump to debug. For example, I press 5 keys and see 5 key down events, but when I releas them, only 2 o 3 note up events are shown. And if I play too many notes, it just stops receiving any events from the device, dmesg show a strange message "urb status -75" and reconnects the usb device. I've googled about that, but couldn't find anything usefull.

I tested the same cable on my old desktop (Asus A7N8X-X motherboard, nvidia MX440 graphics card, 5 years of intensive e loyal use) and it works fine. The difference between the two seems to be the usb module that handles the device. On the laptop, it is uhci_hcd, while on the desktop it is ohci_hcd which is loaded. I've tried all by means I know to use ohci_hcd in the laptop too but I've failed. Some things I remember to have tried:

1 - force the load order in rc.conf (doesn't affect anything)
2 - force the load order in mkinitcpio.conf (doesn't affect anything)
3 - disable uhci_hcd from loading (stops recognizing anything usb related)
4 - using a rt enabled kernel (doesn't affect anything)

Does anyone has any suggestions on how can I force ohci_hcd to be loaded before uhci_hcd?

Last edited by denisfalqueto (2009-06-18 16:30:11)

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Satisfied users don't rant, so you'll never know how many of us there are.

deej

Member

Registered: 2008-02-08

Posts: 395

Re: [Found cause] Midi-usb cable and usb modules loading

Is not uhci for usb 1.1 ? This could be your problem, loading a 1.1 driver in a usb 2.0 slot.
Only a quick thought, as no-one had answered you yet.

Deej

[EDIT]
OK, a quick google gives me ohci as usb 1.1

Last edited by deej (2009-06-17 20:37:20)

denisfalqueto

Member

From: ES, Brazil

Registered: 2006-03-24

Posts: 197

Re: [Found cause] Midi-usb cable and usb modules loading

I was thinking about that too, but ohci works right on the desktop, inspite of being usb 1.1... The crappy cable is suposed to be usb 2.0, but I don't trust it very much. Is a brandless product, probably chinese. I'll try all I can do to avoid buying some serious usb midi cable, but I'm not very hopefull.

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Satisfied users don't rant, so you'll never know how many of us there are.

deej

Member

Registered: 2008-02-08

Posts: 395

Re: [Found cause] Midi-usb cable and usb modules loading

I would be wrong to say "Feckin' Chinese rubbish" - it is often the company out-sourcing the manufacture that
demands costs / corners are cut [ and then sells at full price ! ]. But now, I refuse to buy *anything* made in
China. Needless to say, this means I now make my own shoes and cook in a hole-in-the-ground :lol::lol:

If I come up with a [non-Chinese] solution for your problem, I'll get back to you.

Deej

denisfalqueto

Member

From: ES, Brazil

Registered: 2006-03-24

Posts: 197

Re: [Found cause] Midi-usb cable and usb modules loading

Hahahaha, I was blaming the cable from the start, but it is "almost" innocent at this case. In my desktop it works fine even without any special kernel patch. It seems that the usb hub of my laptop is the one to blame, but I still didn't found any way to make it work right.

The funny thing is that I already have a midi cable for my desktop, which uses the joystick port. I bought the usb cable to use only in the laptop, but never managed it to work. I think I'll have to fork out around $ 100,00 for an M-Audio Uno interface... It is a shame that we have to pay so much for that here in Brazil.

Thanks anyway

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Satisfied users don't rant, so you'll never know how many of us there are.

deej

Member

Registered: 2008-02-08

Posts: 395

Re: [Found cause] Midi-usb cable and usb modules loading

"I think I'll have to fork out around $ 100,00 for an M-Audio Uno interface"
...jeez - @ $40 in the U.S. ; £30 here in G.B. ($49) - Brasil is sure expensive !

Good luck...

Deej

denisfalqueto

Member

From: ES, Brazil

Registered: 2006-03-24

Posts: 197

Re: [Found cause] Midi-usb cable and usb modules loading

Well, just for the record, I had some success with this cable. But I had to use it through a usb pc keyboard that happenst to be a usb hub too. In that way, the notes are not lost and I can play very well (haha, as if I played very well... good one).

So, the problem seems to be some kind of miscontact between the usb plug of the cable and the usb ports of my notebook. This explains also why it just work directly over 2 of the 4 available usb ports, and one of them is really miscontacting. I am searching for an usb extensor cable that I got hidden somewhere to see if I can avoid using the pc keyboard

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Satisfied users don't rant, so you'll never know how many of us there are.