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Re: bus_dmamap_sync() for uhci(4)



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Hello,

On Jun 9, 2008, at 16:16, Manuel Bouyer wrote:

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.

The O2 doesn't have any kind of DMA coherency support IIRC. The only other card I tried in this machine is an ex which Just Worked(tm). So do the onboard ahc's.

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).

Hmm, I need to read sgimips' bus_dma stuff again but since other drivers work it can't be all that borked.

have fun
Michael

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