Re: [gentoo-user] new machine : mouse trouble : finally explained

[Philip Webb]

120914 Volker Armin Hemmann wrote:
> On Thu, Sep 13, 2012 at 10:06:01PM -0400, Philip Webb wrote
>> Both Mageia -- installed from USB stick in a partition on the
>> HDD -- & System Rescue show  /dev/input/mouse0  after booting ;
>> in the case of SR it does it before I enter the GUI via 'wizard'.
>> They have no problem with the 2.0/1.1 port, but the Gentoo system as
>> I've installed it don't show  /dev/input/mouse0 from that port, but
>> only if I plug the mouse into the 3.0/2.0 port.  Someone suggested
>> it is caused by a Kernel .config setting, which if enabled seems to
>> force the system to look in the 3.0 port.  Why it should do that
>> doesn't make much sense : such upgrades are usually permissive,
>> not restrictive.  BTW there's no difference between 3.4.9 & 3.5.3 .
> All AMD southbridges need the OHCI controller driver.

Indeed, you seem to be correct.  The cause was an omitted driver,
which was a side-effect of switching from an Intel to an AMD mobo.
This machine has a Core2 Duo CPU & my .config for Kernel 3.4.0 has

  # USB Host Controller Drivers
  ...
  CONFIG_USB_EHCI_HCD=y
  ...
  # CONFIG_USB_OHCI_HCD is not set
  ...
  CONFIG_USB_UHCI_HCD=y
  ...

If you look at the helps which are available during 'make menuconfig',
they state (in brief) that OHCI is for 1.1 + AMD, UHCI is for Intel,
EHCI is for faster mice using 2.0 & XHCI (new) is for USB 3.0 .
So with a Core2 Duo & a mobo with only USB 2.0 , UHCI is enough ;
for my new AMD Bulldozer X4 FX-4170 4-Core 4,2 GHz , UHCI doesn't work,
but EHCI or XHCI take care of the 2.0/3.0 port, where the mouse works :
to be able to use the mouse in the 1.1/2.0 port, OHCI is needed.

All rather obscure & I can only thank the gods again for jolting my arm
so that I inserted the mouse into the wrong-but-right port.

HTH a few others, who can now find this msg via Google.

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