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Re: bus_dmamap_sync() for uhci(4)

On Mon, Jun 09, 2008 at 03:43:05PM -0400, Michael Lorenz wrote:
> >I just did that. Now the kernel doesn't find /any/ USB devices  
> >except the root hubs. It can't really be a problem with crime  
> >interrupts - ehci finds devices and other cards that used interrupt  
> >10 worked before so at least one of the uhcis should work.
> Hmm, an old, unpatched kernel does find devices at uhci.

thanks. That's strange: if I read things properly, all the memory used
by uhci or ehci should be mapped uncached (use of BUS_DMA_COHERENT),
so the _sync operations I added should just issue wmb() instructions,
nothing more.

BTW, I suspect the lack of memory read/write barrier are the cause of
the issues I'm seeing on x86 too (this is why I started this work).

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

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