[PATCH 1/3] PWM: add pwm framework support

Sascha Hauer s.hauer at pengutronix.de
Thu Jun 30 13:02:29 EDT 2011


On Thu, Jun 30, 2011 at 11:17:54AM -0500, Bill Gatliff wrote:
> Guys:
> On Thu, Jun 30, 2011 at 7:41 AM, Arnd Bergmann <arnd at arndb.de> wrote:
> > A lot of people want to see a framework get merged, and I think it's
> > great that Sascha has volunteered to do the work to push that
> > through this time, especially since you have not been able to
> > finish your work.
> Sascha is wasting his time by reinventing the wheel.  He's traveling
> over exactly the same path I have already covered.  In fact, some of
> his reviewer comments are almost word-for-word the same as those I
> have received and addressed in the past.
> My patches were always kept current in this mailing list and others,
> and Sascha clearly has the skills necessary to make improvements and
> corrections should he have chosen to do so.

I think that you made the fundamental mistake to completly ignore the
existing pwm API and its users. With a competing api we are basically
stuck. We can't convert the existing hardware drivers to the new API
because leds-pwm.c, pwm_bl.c and others still depend on the old API and
boards using it would break. We can't convert the function drivers
either because again this would break boards for which only an old style
pwm driver exists.  So the logical thing to do is to put a step in
between: Consolidate the existing drivers and *then* change the API
atomically so that nothing breaks. Your patches don't do this, so I
don't think at all that what I did is duplication of work.

Given the current rush to move drivers out of arch/ it probably won't
take long until all pwm drivers are moved to drivers/pwm/ and converted
to use the framework, and then you have a good base to put your work onto.
So please don't complain too much: We are currently only doing the work
you didn't want to do.


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