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Subject: Re: [BK PATCH] USB update for 2.6.3
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "David S. Miller" <davem@redhat.com>
Cc: Linus Torvalds <torvalds@osdl.org>, Greg KH <greg@kroah.com>,
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> You miss how all of this stuff is being used :-)
> 
> USB drivers do things like map DMA memory, and the generic DMA layer vectors it
> so that if the USB device is attached to a PCI host the PCI DMA mapping routines
> get used.

Hrm... so if the USB device drivers are actually doing the dma mapping
themselves, it make sense for them to pass their own struct device, no ?

Or do they have always to pass their host controller one ?

In the former case, we need that inheritance stuff. In the later case
we don't. At this point, it's pretty much a matter of policy.

Ben.