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Re: bus_dmamap_sync() for uhci(4)

On Mon, Jun 23, 2008 at 03:11:41AM +0900, Izumi Tsutsui wrote:
> > ...this might be kern/37590. :-/
> I don't think so.
> NVIDIA EHCI has some hardware bug that we don't handle (see PR#37884),
> though it could be fixed by proper bus_dmatag_subregion(9) and
> bus_dmamap_sync(9) calls that Manuel is working on.

Note that we can do bus_dmatag_subregion() without the bus_dmamap_sync()
calls here, because all DMA memory used by the USB subsystem comes from
bus_dmamem_alloc(). I'm adding bus_dmamap_sync() calls here because they
also should cause memory barriers, which are needed to avoid race
condition between host and controller in the DMA descriptors linked lists

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference

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