4 Replies Latest reply on Jun 27, 2014 11:37 AM by sylvia_intel

    Does the Intel USB 3.0 driver for 7-series chipsets support xHCI hand-off?

    misha256

      Hi all,

       

      Intel’s 7-Series chipset supports USB 3.0.  On Windows 7, you need to install Intel’s USB 3.0 driver to enable USB 3.0 functionality.  The driver can be found here:

       

      https://downloadcenter.intel.com/Detail_Desc.aspx?DwnldID=21129

       

      My question is simple but I suspect the answer might be esoteric:  Does this driver support xHCI hand-off?

       

      More info for those who are interested:

       

      The BIOS normally "owns" the USB 3.0 (xHCI) controller when you first power on the PC.  Eventually the OS loads.  Lets assume the OS supports USB 3.0.  If the OS also supports xHCI hand-off, it will obtain exclusive control of the USB 3.0 controller from the BIOS.  If it doesn't support xHCI hand-off, bad things will happen (i.e. the BIOS and OS may try to use the controller at the same time).

       

      Now Windows 7 doesn't natively support USB 3.0.  However, the Intel driver enables USB 3.0 support.  But, does it also enable xHCI hand-off support?

       

      The question is important because of this:

      ehci-xhci-handoff.jpg

      These are special USB settings in my PC's BIOS.  The BIOS manual says this:

      My thinking is that, if the Intel USB 3.0 driver has xHCI hand-off support, then I should disable the XHCI Hand-off setting in the BIOS.  While we're at it, seems obvious that the EHCI Hand-off setting also needs to be disabled.  Then again, my thinking could be totally wrong... so I'm hoping for some definitive answers on this from the experts! :-)

       

      Michal