Re: [PATCH v9 00/11] PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM) (a subset)

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
	Sudeep Holla <sudeep.holla@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Linux PM <linux-pm@vger.kernel.org>,
	Tony Lindgren <tony@atomide.com>,
	Kevin Hilman <khilman@kernel.org>,
	Lina Iyer <ilina@codeaurora.org>,
	Rob Herring <robh+dt@kernel.org>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	linux-arm-msm <linux-arm-msm@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v9 00/11] PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM) (a subset)
Date: Fri, 5 Oct 2018 11:47:29 +0100	[thread overview]
Message-ID: <20181005104729.GB25651@red-moon> (raw)
In-Reply-To: <CAPDyKFrWzDU9BsfAnx7uoaXq=gmGg2r46Mn-cJHSWUk-TmyomA@mail.gmail.com>

On Thu, Oct 04, 2018 at 08:36:24PM +0200, Ulf Hansson wrote:
> On 4 October 2018 at 19:21, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote:
> > On Thu, Oct 04, 2018 at 07:07:27PM +0200, Rafael J. Wysocki wrote:
> >
> > [...]
> >
> >> > > I don't see any dependency there, so I'll queue up the 1-3 in
> >> > > pm-domains and the 4-6 in pm-cpuidle.
> >> >
> >> > I do not see why we should merge patches 4-6 for v4.20; they add legacy
> >> > (DT bindings and related parsing code) with no user in the kernel; we
> >> > may still want to tweak them, in particular PSCI DT bindings.
> >>
> >> My impression was that 4-6 have been agreed on due to the ACKs they
> >> carry.  I'll drop them if that's not the case.
> >
> > I have not expressed myself correctly: they have been agreed (even
> > though as I said they may require some tweaking) but I see no urgency
> > of merging them in v4.20 since they have no user. They contain DT
> > bindings, that create ABI/legacy, I think it is better to have code
> > that uses them in the kernel before merging them and creating a
> > dependency that is not needed.
> 
> There is already code using the new bindings, for the idle states.
> Please have look at patch 5, 6 and 11.

I had a look before replying and I reiterate the point, there is
no reason to merge those patches without the rest of the series,
none. There is already a way to describe idle states in the kernel
and it works very well, we will add one when we need it not before.

> Moreover, you have had plenty on time to look at the series, as those
> patches haven't changed since a very long time.

So ?

> May I suggest you do the review instead, so we can move things
> forward, please. The changes in the v9 series should be trivial to
> review.

There is no reason to merge patches [4, 5, 6, 10] stand-alone, they
are not solving any problem and they do not provide any benefit
other than adding useless ABI/legacy, they make sense when we look
at the whole series.

> >> > Likewise, it makes no sense to merge patches 7-8 without the rest of
> >> > the PSCI patches.
> 
> Well, those patches are part of this series, because Mark wanted me to
> move the files. Is really such a big deal? I think it makes sense, no
> matter what happens afterwards.

We can merge patches [7-8] even if there is no urgency at all to do so,
usually PSCI patches go via arm-soc whose patches queue is now closed
and I do not think that's a problem at all.

Lorenzo