Re: [RFC 2/6] omap: iovmm: generic iommu api migration

From: Ohad Ben-Cohen
Date: Tue Jun 07 2011 - 09:46:51 EST


Hi Laurent,

On Tue, Jun 7, 2011 at 2:26 PM, Laurent Pinchart
<laurent.pinchart@xxxxxxxxxxxxxxxx> wrote:
>> Right now we have a BUG_ON if pa is unaligned, but that can be changed
>> if needed (do we want it to handle offsets ?).
>
> At least for the OMAP3 ISP we need to, as video buffers don't necessarily
> start on page boundaries.

Where do you take care of those potential offsets today ? Or do you
simply ignore the offsets and map the entire page ?

Seems like omap's iommu (mostly) rejects unaligned pa addresses, see:

4abb761749abfb4ec403e4054f9dae2ee604e54f "omap iommu: Reject unaligned
addresses at setting page table entry"

(this doesn't seem to cover 4KB entries though, only large pages,
sections and super sections)

> A separate patch is indeed needed, yes. As you're already working on iommu it
> might be simpler if you add it to your tree.

Sure, i'll send it.

Thanks,
Ohad.
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