Re: [PATCH 2/2] clk: ti: Add support for dm814x ADPLL

[Michael Turquette <mturquette@baylibre.com>]

Quoting Tony Lindgren (2016-02-17 13:20:46)
> * Michael Turquette <mturquette@baylibre.com> [160217 12:53]:
> > Quoting Tony Lindgren (2016-02-17 09:39:49)
> > > * Michael Turquette <mturquette@baylibre.com> [160216 17:32]:
> > > > =

> > > > We have a shiny new series that provides a standard way to do this:
> > > > =

> > > > http://lkml.kernel.org/r/<1455225554-13267-1-git-send-email-mturque=
tte@baylibre.com>
> > > =

> > > OK nice, so tagging the MPU and DDR clocks with CLK_IS_CRITICAL or
> > > "clock-critical" should allow removing this code. I think in this
> > > case I still need to set CLK_IS_CRITICAL as the clock is output 1
> > > of the dts defined clock and does not have a separate dts node.
> > =

> > In fact I hate clock-critical as a DT property and it's only there to
> > support legacy DT bindings that store all clk data in DT and have zero
> > clk data in C. So please use the CLK_IS_CRITICAL or CLK_ENABLE_HAND_OFF
> > flags in C.
> > =

> > Do you think you will ever have a driver that wants to gate these
> > clocks? Probably not for MPU/DDR, but the HAND_OFF flag is a better fit
> > if you do. It's the same as CRITICAL but transfers the prepare/enable
> > reference counting to the consumer driver after that driver calls
> > clk_get() and clk_prepare_enable() on the HAND_OFF clk.
> =

> OK I'll use CLK_ENABLE_HAND_OFF then. Who knows maybe somebody
> somewhere has code running on one of the coprocessors in SRAM that
> actually allows gating these :)

Low power mp3 decoder executing out of ARM icache with DDR clock cut ;-)

Regards,
Mike

> =

> > > I can update when those patches hit Linux next, or I can do a
> > > follow-up patch later on if we want to avoid the dependency
> > > here. Which do you prefer?
> > =

> > Well, testing is always welcome :-)
> >
> > If you rebase onto those patches then I'll add your patches to that
> > series for testing and merge it that way.
> =

> OK will do and repost after some testing.
> =

> Regards,
> =

> Tony