From mboxrd@z Thu Jan  1 00:00:00 1970
From: ohad@wizery.com (Ohad Ben-Cohen)
Date: Tue, 7 Jun 2011 16:46:26 +0300
Subject: [RFC 2/6] omap: iovmm: generic iommu api migration
In-Reply-To: <201106071326.53106.laurent.pinchart@ideasonboard.com>
References: <1307053663-24572-1-git-send-email-ohad@wizery.com>
	<201106071105.16262.laurent.pinchart@ideasonboard.com>
	<BANLkTi=nJXSEfWRXqwnHys1b5i5rgLcYpw@mail.gmail.com>
	<201106071326.53106.laurent.pinchart@ideasonboard.com>
Message-ID: <BANLkTimqt=yMGHcqEH5u-4GkMX9=+BuB6A@mail.gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Laurent,

On Tue, Jun 7, 2011 at 2:26 PM, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> 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.