[RFC][PATCH] plat-mxc: iomux-v3.h: implicitly enable pull-up/down when that's desired

[Paul Fertser]

On Wed, Oct 12, 2011 at 10:27:02AM +0200, Sascha Hauer wrote:
> On Mon, Oct 10, 2011 at 11:19:23AM +0400, Paul Fertser wrote:
> > This leads to some rather hard to understand bugs such as
> > misdetecting an absent ethernet PHY (a real bug i had)
...
> > This might affect mx25, mx35, mx50, mx51 and mx53 SoCs.
...
> > I'm not sure if that's really suitable for -stable so please excuse me
> > if it's not.
> 
> I think it's not suitable for stable unless there is a real bug, that
> is PUE or PKE are forgotten somewhere.

If there wasn't a real bug with MDIO, i wouldn't have found the
problem. I've also checked all other potentially affected SoCs and all
of them (except for the mx35, whose iomux file doesn't configure any
pads at all) had some suspicious entries.

> I don't like that the defines which are supposed to be defines for
> the individual bits are changed. This may lead to trouble and confusion
> once someone wants to read the values from the iomux registers and
> tests for bits. How about Adding new defines like this instead:

I perfectly understand the reasoning and fully agree it would be best
to do it that way right from the beginning. But given the current
situation when many affected iomux headers share the error that can
lead to subtle strange bugs, i thought it might be beneficial to fix
them all implicitly. And testing for those pull-up bits set without
testing for PUE/PKE doesn't seem to be of any use, and also before
sending a patch i did a git grep and found no examples of using those
constants in an unexpected way.

If you still prefer the cleaner way, i can also do that and correct
all the suspicious entries manually, just let me know.

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