Re: usbd does not use detach

In message: <20030815111809.06960905.eaja_at_erols.com>
            Eric Jacobs <eaja_at_erols.com> writes:
: On Thu, 14 Aug 2003 10:38:07 -0700
: John-Mark Gurney <gurney_j_at_efn.org> wrote:
: 
: > 
: > This is a bit more complex than this.  There are many more layers between
: > usb and VFS.  For USB umass devices, they proxy to cam, which then is an
: > interface to da which is a provider for geom which then provides the
: > final device for ufs to mount.  So, each and every one of those steps
: > need to be taught about this.  Right now, very few things use newbus
: > even though they should.  This is a problem of them existing before
: > newbus was nailed down.  CAM doesn't use newbus for any of it's device
: > management (scsi device, not HBA attachment).
: 
: Yes, I'm aware that there are more layers. Propogating the flag value
: down is trivial. The major deficiency of CAM and GEOM is that errors
: can't be sent back up. For example, we have this scenario:
: 
: # mount /dev/da0s1a /mnt          # mounting a USB hard drive
: # cd /mnt                         # in use
: # kldunload umass                 # oops! it succeeds
: #
: 
: Ideally, I'd love to see an enhanced newbus provide the One True
: Framework for attaching and detaching both devices and device
: clients. Unfortunately, it seems like it would take a substantial
: redesign to get there from this point.

Nah, just to make cam use it. cam and newbus were contemporary
developments, so cam used the old ad-hoc way of dealing.

Warner