Re: kue0 not receiving patch

[Joerg Sonnenberger <joerg@xxxxxxxxxxxxxxxxx>]

On Wed, Feb 16, 2005 at 10:01:09AM -0800, Matthew Dillon wrote:
>     Looks reasonable Joerg.  You are now in charge of sequencing the commit
>     in and getting feedback /verifying it with the people using USB ethernet.
>     :-)

Alright :)

I've been looking at the USB stack for a way to remove the ISR hacks
and other related issues.

The basic problem is that the host controller (ohci, ehci, uhci) doesn't
know which interrupt types are possible. We have three basic options to do
it correct I think.

(a) add a USB IPL which can be used by the ?HCI to protect internally
    against races and has a lower priority than all the other masks
    [read: is masked by them]
(b) add a facility to specify the interrupt mask with nexus_setup_intr
    directly and be allowed to change that later. This is the easiest
    solution and would allow us to implement something similiar to
    intr_mux for the *HCI interrupt handling. USB drivers could use
    the same protection mechanism as normal drivers and specify the own
    mask directly.
(c) switch to soft interrupt style handling like NetBSD already does.
    This has the advantage of fitting into the DF style, but I'm not
    sure yet how much work it is. I have to look at the implementation
    of the taskqueue framework.

Joerg