Re: [discuss] Re: kgdb for x86_64 2.6 kernels

Greg KH
2004-01-15T00:24:26Z

On Wed, Jan 14, 2004 at 04:02:45PM -0800, George Anzinger wrote:
> Greg KH wrote:
> >On Wed, Jan 14, 2004 at 12:02:02PM -0800, George Anzinger wrote:
> >
> >>Right. I had hoped that we might one day be able to use the USB and I am
> >>sure there are others.
> >
> >
> >Raw USB? Or some kind of USB to serial device?
> >
> >Remember, USB needs interrupts to work, see the kdb patches for the mess
> >that people have tried to go through to send usb data without interrupts
> >(doesn't really work...)
>
> I gave up on USB when I asked the following questions:
> 1. How many different HW USB master devices need to be supported (i.e.
> appear on your normal line of MBs)? (answer, too many)

There are only 3, UHCI, OHCI, and EHCI. You can forget about EHCI, as
all EHCI controllers contain either a UHCI or OHCI controller embedded
in them (EHCI only handles the USB2 high speed data.) So you really
only have to handle 2.

> 2. Can I isolate a USB port from the kernel so that it does not even know
> it is there? (answer: NO)

Sorry, this is correct. Unless you want to take over the whole pci
device that the USB controller is on. That's a possiblity you might
want to look into.

thanks,

greg k-h