Re: [PATCH] spi: spi_mpc8xxx.c: fix potential memory corruption.

[Anton Vorontsov <cbouatmailru-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Thu, May 13, 2010 at 11:36:15AM +0200, Joakim Tjernlund wrote:
[...]
> The new QE mode is so broken :(
> Notice how the byte order is swapped for word = 16, 32

*yawn*, it's not a news... :-) Remember QE-specific rx/tx_shift
stuff?

I'm sure the issue is related to how the QE SPI shift register
works. I.e. SDMA just feeds the shift register, and it's shift
register that is causing > 8 bits words to misbehave, or the
issue is in how SDMA and shift registers connected.

> Not even sure what is right to begin with :)
> Can't see how one should fix this either.

I guess by copying the whole buffer, shifting bytes back and
forth, remapping it, doing transfer, and copying data back.
I think that'll work, but no idea how efficient that will be.

Also, I'd not do that for CPM hardware, I tend to believe
that it's not affected.

-- 
Anton Vorontsov
email: cbouatmailru-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org
irc://irc.freenode.net/bd2

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