Re: [PATCH v4 03/26] clk: sunxi-ng: Add check for maximum rate to NKM PLLs

From: Jagan Teki <jagan@amarulasolutions.com>
To: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Chen-Yu Tsai <wens@csie.org>, Icenowy Zheng <icenowy@aosc.io>,
	Jernej Skrabec <jernej.skrabec@siol.net>,
	Vasily Khoruzhick <anarsoul@gmail.com>,
	Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	David Airlie <airlied@linux.ie>,
	dri-devel <dri-devel@lists.freedesktop.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Stephen Boyd <sboyd@kernel.org>,
	linux-clk <linux-clk@vger.kernel.org>,
	Michael Trimarchi <michael@amarulasolutions.com>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
	devicetree <devicetree@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-sunxi@googlegroups.com, linux-amarula@amarulasolutions.com
Subject: Re: [PATCH v4 03/26] clk: sunxi-ng: Add check for maximum rate to NKM PLLs
Date: Tue, 20 Nov 2018 17:37:11 +0530	[thread overview]
Message-ID: <CAMty3ZAbF8rPsmvXdLPQJfHL7bzeQyL0Psii9gyDiHaZW-UaMg@mail.gmail.com> (raw)
In-Reply-To: <20181120105557.3mysirc3ga2h2334@flea>

On Tue, Nov 20, 2018 at 4:26 PM Maxime Ripard <maxime.ripard@bootlin.com> wrote:
>
> On Thu, Nov 15, 2018 at 08:51:04PM +0530, Jagan Teki wrote:
> > > >  drivers/clk/sunxi-ng/ccu_nkm.c | 3 +++
> > > >  drivers/clk/sunxi-ng/ccu_nkm.h | 1 +
> > > >  2 files changed, 4 insertions(+)
> > > >
> > > > diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> > > > index 6b5ad990f802..b8b66cdd30bf 100644
> > > > --- a/drivers/clk/sunxi-ng/ccu_nkm.c
> > > > +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> > > > @@ -128,6 +128,9 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
> > > >       if (rate < nkm->min_rate)
> > > >               return nkm->min_rate;
> > > >
> > > > +     if (nkm->max_rate && rate > nkm->max_rate)
> > > > +             return nkm->max_rate;
> > > > +
> > >
> > > I would expect the test to be the same for the minimum and maximum cases.
> >
> > I don't have proper use-case for max rate test, I do verify by using
> > higher the rate on dclock, but nor sure.  May be I can skip the
> > max_rate patch?
>
> So you're sending more patches that you haven't really tested?

I didn't understand this question.

> Why are you sending them then?

I think I've mentioned in the first version patch itself, since it's
common code and many other callers might have used for rate
alternative I did it how other ccu dividers does. I have not added
just as simple.
>
> > Apart from this, any idea about this issue where SUN4I_TCON0_DCLK_REG
> > will only work with div upto 6 on A64 DSI panels[1], did you find the
> > same issue on A33?
>
> IIRC my panel was falling into the case where the divider was 4, so
> I've not fallen into that case.

OK, thanks.