Re: [PATCH] mmc: add SDHCI driver for STM platforms.

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 2 Aug 2010 15:36:31 +0100
Matt Fleming <matt@console-pimps.org> wrote:

> > > What is devm_stm_pad_claim()? I can't find this function in linus'
> > > tree, or in -next, or in Andrew's -mm series. Where is this function
> > > from?
> > 
> > This comes from our STMicroelectronics platform pad management
> > infrastructure; code available from:
> > http://git.stlinux.com/?p=stm/linux-sh4-2.6.32.y.git;a=summary It's
> > used to claim/manage various resources i.e. PIO and clock lines.
> 
> That's interesting. So, this driver won't build with linus' tree? I
> didn't think that the kernel catered for external interfaces like this
> - it causes all sorts of issues, not least of which is the fact that
> the driver can't be built or tested with the mainline kernel.
> 
> Andrew, what do you make of this?

It definitely needs to be compileable.  Otherwise it's dead code to
everyone else and nobody can maintain it as they make tree-wide or
subsystem-wide changes.

Also I do think the code in mainline should be able to be excecutable
(and testable!) without external code dependencies.  This gets into the
realm of licensing concerns: is the out-of-tree code GPL?  If not then
people will make a big fuss.  If it _is_ GPL then get it merged up!