# OHCI vs UHCI questions.

## vash

My new computer upgrade has been done with a MSI K7D-L Master board, that has the 760MPX chipset.  With the install of Gentoo, I had no problems with installing Geintoo, but after I reboot, I am having problems with my USB just locking up and requiring a restart.  When I am using the cli, my keyboard input would all of a sudden just stop and I'd have to unplug and replug the keyboard to get any input back at all.

By default, with gentoo-sources, the USB support is setup for UHCI.  I recompile the kernel, with just OHCI support and my issues are nearly gone (when it does freeze, its for a second or so only).  The funny thing is, the manual states UHCI and I figured I'd be good with that.  If anyone can shed some light on these USB pauses, I'd greatly appreciate it.

vash

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## BonezTheGoon

Well one interesting tid-bit I found on the MSI product page indicates that you have USB 2.0 on this board.  Perhaps you would have better support enabling the 2.0 version than the default 1.1 version?  Just a guess and simply my first thought once I pulled up the product page.  I know that originally this chipset had big problems with USB onboard, and so ASUS and Soyo (or maybe it was Tyan) were shipping without onboard USB and the only USB support was through the PCI USB card that came with the package.  So is your USB a card or is it onboard/integrated?

Regards,

BonezTheGoon

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## vash

The board revision I have is with the onboard USB southbridge, version 1.1.  And no, I'm not using the PCI 2.0 card that was supplied, but rather, the onboard USB controller.  The newer USB 2.0 card is installed, but I'm still using the onboard controller.

vash

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## BonezTheGoon

Yeah just to clear up my earlier post, apparently AMD did fix the southbridge (according to these guys anyway, who go nuts over how good this board is!)

By the way, I am now feeling Mainboard envy.  I hope someone smarter, or more experienced at least, than me can find this thread and give you something better to go off of.  I have no trouble with USB, so I haven't learned any snazzy tricks yet.

I do find it interesting that both UHCI and OHCI seem to give you functional ports.  Maybe we can find some specifics on AMD's 761MPX that can tell us which is supposed to be used.  I'll see what I can find!

Regards,

BonezTheGoon

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## BonezTheGoon

You might want to check which version of the southbridge you actually have.  Looking at this pdf file from AMD it indicates a problem (that near as I can tell has not been fixed in ANY revision of the southbridge) but it does not sound like what you are expierencing anyway.  Never the less, it could still be helpful.  I was simply digging for chipset documentation that should indicate what to use (UHCI or OHCI.)

Regards,

BonezTheGoon

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## BonezTheGoon

OK I found what I was originally looking for in this pdf file also from AMD (look on page 5).  OHCI is the correct support to use for the 760MPX family of chipsets.

Regards,

BonezTheGoon

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