Re: [RFC v2 1/2] PCI-Express Non-Transparent Bridge Support

[Jianbin Kang]

> Actually this is what I'm working on now, using async_tx to replace the
> memcpy.  I believe the changes shouldn't be that significant.
>
> Is the "hardware that can setup dma" you refer to something that does
> not use this interface?
>

Yes, they use this interface, but split 'memcpy_toio' to two operation:
     1. setup dma
     2. wait/poll for the dma to finish.
So maybe it need to provide a generic function 'tx' for different hardwares.

If async_tx is available, it's much better than this 'sync dma/memcpy'.
One problem with async_tx is, it can't detect memcpy error.
If the remote ntb goes down when async_memcpy is in operation, async_tx
will trigger an oops.
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