loadable drivers

[M. Warner Losh]

In message: <18678.7732.431604.484585 at gromit.timing.com>
            John Hein <jhein at timing.com> writes:
: Bernd Walter wrote at 18:21 +0200 on Oct 15, 2008:
:  > On Tue, Oct 14, 2008 at 04:32:30PM -0600, John Hein wrote:
:  > > M. Warner Losh wrote at 15:34 -0600 on Oct 14, 2008:
:  > >  > In message: <20081015003842.a2bd682b.stas at FreeBSD.org>
:  > >  >             Stanislav Sedov <stas at freebsd.org> writes:
:  > >  > : On Tue, 14 Oct 2008 14:25:32 -0600
:  > >  > : John Hein <jhein at timing.com> mentioned:
:  > >  > : 
:  > >  > : > What needs to be done to support loadable drivers under arm/freebsd?
:  > >  > : 
:  > >  > : I think they should work, aren't they?
:  > >  > 
:  > >  > Build them...  They work..
:  > > 
:  > > Sorry for the poor problem statement.  They do load, but I'm not
:  > > getting into the probe or attach.  At first I thought the load
:  > > was failing, but that was driver error (pardon the pun).
:  > 
:  > Then it is likely a driver or configuration specific problem.
:  > One of the possible reasons is that you may missing hints, because many
:  > devices in embedded systems don't support probing.
:  > IIRC I already successfully loaded USB modules on AT91.
: 
: Yes, it was my error... missing identify method.  I've been using
: drivers parented to self-identifying busses for so long, I forgot
: that important little detail.
: 
: Sorry for the gross misdirection.
: 
: Note that loading the uftdi driver via kldload behaves differently on
: arm than when it's compiled into the kernel.  It boils down to
: uaa->iface being NULL (in uftdi_match) in the former case and not NULL
: in the latter.  I haven't tracked that down yet, but kldload works
: fine on x86.

There's issue with loading usb drivers because it was never designed
for that...  Some drivers work, others don't.

Warner