[PATCH 3/4] of/gpio: Implement GPIOLIB notifier hooks

[Grant Likely]

On Fri, Mar 5, 2010 at 10:05 PM, Anton Vorontsov
<avorontsov at ru.mvista.com> wrote:
> On Fri, Mar 05, 2010 at 08:54:56PM -0700, Grant Likely wrote:
> [...]
>> The last version of the patches were posted on Feb 8.  -rc8 was
>> released on Feb 12.  For changes to common code, that is a little late
>> for getting queued up for the merge window.  If it was a subsystem
>> that I maintain, say SPI, then I doubt I would have picked it up for
>> 2.6.34.
>
> And of course the part of the OF rework, which was first posted
> for *review* on Feb 03, is a completely different story?
>
>  48 files changed, 317 insertions(+), 575 deletions(-)

Completely uncontroversial changes with zero functional behaviour
change.  There was no uncertainty about these ones and they were
posted almost a week earlier.

> It's in Linus' tree now.
>
> And the other part of the OF rework that was posted for review
> on Feb 13 is another story too? It's in Linus' tree as well.

All cleanups and bugfixes except for "Don't assume HAVE_LMB" which
Jeremy had already posted earlier for review.

> Your patches touch 3 architectures, and a lot of the code that
> is used by all the OF drivers, still 03 and 13 Feb was OK for
> them.
>
>> But I am not the GPIO maintainer.
>
> David is. And I heard only positive feedback on the patches
> last time.
>
>> For the record, my main concerns are:
>> - Now that I see the implementation, I think that it is too complex.
>> The bus notifiers really aren't needed and it can be done with much
>> lower impact on the core gpiolib code.
>
> That's a non-argument, what is "lower impact"? Do I touch any
> hot paths? And if nothing has changed, David (again, the gpiolib
> maintainer) is happy with the notifiers approach, why would you
> care?

Adding unneeded notifier infrastructure is churn I don't want to see.

>> Changes to common code don't work that way.  Sometimes things just
>> don't get enough attention and they wait another cycle, get reworked,
>> or get dropped entirely.
>
> See above wrt OF rework patches.

which all got attention, were uncontroversial, and did not introduce
functional changes.

>> For one, the device node pointer is moving out of archdata into
>> 'struct device' proper and I've got patches adding OF hooks into the
>> core of the platform bus.  If those patches look good to GregKH, then
>> I'll be pursing the same pattern for the other bus types (i2c, spi,
>> etc), and it will be further argument for putting the OF hooks
>> directly into gpiolib instead of using a notifier.  I'll be posting
>> the patches as soon as the merge window closes.
>
> I don't get it. Why is it a problem to change your patches that
> ought to be queued for 2.6.*35*?

It's not, and they are going to be queued for 2.6.35.  In fact, I
didn't posted them this week to avoid adding confusion to the merge
window.  The issues isn't changing my patches.  It is that I don't
like the notifier approach, and I intend to prove that it can be done
in a better way.

g.

-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.