On Thu, Sep 30, 2010 at 05:57:10PM -0700, Dan Williams wrote:

[ adding Greg ]

On Thu, Sep 30, 2010 at 5:16 PM, Tirumala Marri [off-list ref] wrote:

quoted

quoted

Where ?iop_adma_alloc_slots() is implemented differently between
iop13xx and iop3xx. ?In this case why does ppc440spe-adma.h exist? ?If
it has code specific to ppe440spe it should just live in the ppe440spe
C file. ?If it is truly generic it should move to the base adma.c
implementation. ?If you want to reuse a ppe440spe routine just link to
it.

[Marri]That is how I started changing the code. And I see tons of warnings
Saying "Used but not defined" or "Defined but not used". How should I
suppress
Some functions from adma.c are used in ppc440spe-adma.c and some from
ppc440spe-adma.c
Are used in adma.c.

This is part of defining a common interface.  Maybe look at the
linkages of how the common ioat_probe() routine is used to support all
three versions of its dma hardware.

quoted

So I created intermediate file ppc440spe-adma.h with
inlined
Functions. In future this will be converted into ppc4xx_adma.h and move
existing
SoC specific stuff to ppc440spe-adma.c file.

You definitely need to be able to resolve "used but not defined" and
"defined but not used" warnings before tackling a driver conversion
like this.  In light of this comment I wonder if it would be
appropriate to submit your original driver, that just duplicated
routines from the ppc440spe driver, to the -staging tree.  Then it
would be available for someone familiar with driver conversions to
take a shot at unifying.

Greg, is this an appropriate use of -staging?

Possibly, but I really don't like duplication if possible.  What's
keeping this code from being fixed up now properly?

thanks,

greg k-h