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Date: Thu, 25 Oct 2012 19:48:09 +0530
Message-ID: <CAKohpom5QmO5vbREsMgi4EefLpBxXsk=QWVaZwTwC_Knf72GVA@mail.gmail.com>
Subject: Re: [PATCH] dt: add helper function to read u8 & u16 variables & arrays
From: Viresh Kumar <viresh.kumar@linaro.org>
To: Rob Herring <robherring2@gmail.com>
Cc: grant.likely@secretlab.ca, spear-devel@list.st.com,
        devicetree-discuss@lists.ozlabs.org, linux-kernel@vger.kernel.org,
        andriy.shevchenko@intel.com
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On 25 October 2012 18:49, Rob Herring <robherring2@gmail.com> wrote:
> For some reason, this does not show up on the list either in my mail or
> mail list archives, but it is in patchwork. Can you resend it please.

Strange. I kept you in --to field. I know people added in cc are
sometimes removed
by the list when they have selected "avoid duplicate mails" option for
their list.

> The main question I have is be32_to_cpup() the right thing to do. I
> would expect byte arrays to not need endian conversion, but I haven't
> looked at how '/bits/ x' data is stored.

The problem i see here is:

The data passed via DT comes as Little Endian in the kernel.

For a little endian system, byte zero will contain the data and so
(u8) val

look to be the correct thing.

For a big endian system, byte 3 will contain data as it is swapped by
be32_to_cpup.
So (u8) val would return value stored by byte 0 instead. ??

Does my logic look correct to you??

--
viresh
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