Re: [PATCH 2/3] USB: HCD: Add driver hooks for (un)?map_urb_for_dma

From: Alan Stern
Date: Thu Jan 27 2011 - 11:01:53 EST


On Wed, 26 Jan 2011, Robert Morell wrote:

> Provide optional hooks for the host controller driver to override the
> default DMA mapping and unmapping routines. In general, these shouldn't
> be necessary unless the host controller has special DMA requirements,
> such as alignment contraints. If these are not specified, the
> general usb_hcd_(un)?map_urb_for_dma functions will be used instead.
> Also, pass the status to unmap_urb_for_dma so it can know whether the
> DMA buffer has been overwritten.
>
> Finally, add a flag to be used by these implementations if they
> allocated a temporary buffer so it can be freed properly when unmapping.
>
> Signed-off-by: Robert Morell <rmorell@xxxxxxxxxx>

Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

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