From: Rob Herring <robherring2@gmail.com>
To: Viresh Kumar <viresh.kumar@linaro.org>,
Stephen Boyd <sboyd@codeaurora.org>
Cc: Rafael Wysocki <rjw@rjwysocki.net>,
"linaro-kernel@lists.linaro.org" <linaro-kernel@lists.linaro.org>,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
Arnd Bergmann <arnd.bergmann@linaro.org>,
Nishanth Menon <nm@ti.com>, Mark Brown <broonie@kernel.org>,
Mike Turquette <mike.turquette@linaro.org>,
Grant Likely <grant.likely@linaro.org>,
Olof Johansson <olof@lixom.net>,
Sudeep Holla <Sudeep.Holla@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
Viswanath Puttagunta <viswanath.puttagunta@linaro.org>,
Lucas Stach <l.stach@pengutronix.de>,
Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Thomas Abraham <ta.omasab@gmail.com>,
Abhilash Kesavan <kesavan.abhilash@gmail.com>,
Kevin Hilman <khilman@linaro.org>,
Santosh Shilimkar <santosh.shilimkar@oracle.com>
Subject: Re: [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT
Date: Wed, 17 Jun 2015 08:47:35 -0500 [thread overview]
Message-ID: <CAL_Jsq+SdgAf7=Yq7Jk_1d9jTpAOLCEuEDCZvD=-h=2MWsNfFw@mail.gmail.com> (raw)
In-Reply-To: <20150617133314.GB15153@linux>
On Wed, Jun 17, 2015 at 8:33 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 17-06-15, 08:23, Rob Herring wrote:
>> > + operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>;
>>
>> You've made a fundamental change here in that this can now be a list
>> of phandles. There should be some description on what a list means
>> (merge the tables?, select one?).
>
> Did you miss the description I wrote few lines earlier or are you
> asking for something else? This is what I wrote earlier:
>
>> > +Devices may want to choose OPP tables at runtime and so can provide a list of
>> > +phandles here. But only *one* of them should be chosen at runtime.
>
> So, clearly only ONE of the tables should be used.
Yes, never mind.
>
>> I think this needs to have a defined order and the platform should
>> know what that is. For example, if you read the efuses and decide you
>> need the "slow" table, you know to pick the first entry. Then you
>> don't need opp-name. Does that work for QCom?
>
> Why forcing on the order here? For example, consider a case where the
> platform can have four tables, A B C D. Now DT is free to pass all
> four or just a subset of those. Like, for some boards table B doesn't
> stand valid. And so it may wanna pass just A C D. And so keeping these
> tables in order is going to break for sure. Flexibility is probably
> better in this case.
Defined order is a key part of DT bindings. We solve the variable
length problem with name lists associated with variable length
property like:
operating-point-names = "slow", "fast";
I'm not a fan of doing this if we can avoid it, but we should at least
follow the same pattern. Don't send me a patch with that yet, I want
to hear from Stephen.
You can also use "status" to disable specific tables rather than
removing from the list.
Rob
WARNING: multiple messages have this Message-ID (diff)
From: robherring2@gmail.com (Rob Herring)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT
Date: Wed, 17 Jun 2015 08:47:35 -0500 [thread overview]
Message-ID: <CAL_Jsq+SdgAf7=Yq7Jk_1d9jTpAOLCEuEDCZvD=-h=2MWsNfFw@mail.gmail.com> (raw)
In-Reply-To: <20150617133314.GB15153@linux>
On Wed, Jun 17, 2015 at 8:33 AM, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 17-06-15, 08:23, Rob Herring wrote:
>> > + operating-points-v2 = <&cpu0_opp_table_slow>, <&cpu0_opp_table_fast>;
>>
>> You've made a fundamental change here in that this can now be a list
>> of phandles. There should be some description on what a list means
>> (merge the tables?, select one?).
>
> Did you miss the description I wrote few lines earlier or are you
> asking for something else? This is what I wrote earlier:
>
>> > +Devices may want to choose OPP tables at runtime and so can provide a list of
>> > +phandles here. But only *one* of them should be chosen at runtime.
>
> So, clearly only ONE of the tables should be used.
Yes, never mind.
>
>> I think this needs to have a defined order and the platform should
>> know what that is. For example, if you read the efuses and decide you
>> need the "slow" table, you know to pick the first entry. Then you
>> don't need opp-name. Does that work for QCom?
>
> Why forcing on the order here? For example, consider a case where the
> platform can have four tables, A B C D. Now DT is free to pass all
> four or just a subset of those. Like, for some boards table B doesn't
> stand valid. And so it may wanna pass just A C D. And so keeping these
> tables in order is going to break for sure. Flexibility is probably
> better in this case.
Defined order is a key part of DT bindings. We solve the variable
length problem with name lists associated with variable length
property like:
operating-point-names = "slow", "fast";
I'm not a fan of doing this if we can avoid it, but we should at least
follow the same pattern. Don't send me a patch with that yet, I want
to hear from Stephen.
You can also use "status" to disable specific tables rather than
removing from the list.
Rob
next prev parent reply other threads:[~2015-06-17 13:47 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-04 16:20 [PATCH V7 0/3] OPP: Introduce OPP (V2) bindings Viresh Kumar
2015-06-04 16:20 ` Viresh Kumar
[not found] ` <cover.1433434659.git.viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2015-06-04 16:20 ` [PATCH V7 1/3] OPP: Add new bindings to address shortcomings of existing bindings Viresh Kumar
2015-06-04 16:20 ` Viresh Kumar
2015-06-04 18:37 ` Stephen Boyd
2015-06-04 18:37 ` Stephen Boyd
2015-06-05 2:41 ` Viresh Kumar
2015-06-05 2:41 ` Viresh Kumar
2015-06-16 13:34 ` Nishanth Menon
2015-06-16 13:34 ` Nishanth Menon
2015-06-04 16:20 ` [PATCH V7 2/3] OPP: Allow multiple OPP tables to be passed via DT Viresh Kumar
2015-06-04 16:20 ` Viresh Kumar
2015-06-17 13:23 ` Rob Herring
2015-06-17 13:23 ` Rob Herring
2015-06-17 13:33 ` Viresh Kumar
2015-06-17 13:33 ` Viresh Kumar
2015-06-17 13:47 ` Rob Herring [this message]
2015-06-17 13:47 ` Rob Herring
2015-06-17 14:42 ` Viresh Kumar
2015-06-17 14:42 ` Viresh Kumar
2015-06-18 1:30 ` Stephen Boyd
2015-06-18 1:30 ` Stephen Boyd
2015-06-18 2:25 ` Viresh Kumar
2015-06-18 2:25 ` Viresh Kumar
2015-06-18 2:50 ` Viresh Kumar
2015-06-18 2:50 ` Viresh Kumar
2015-06-19 18:47 ` Stephen Boyd
2015-06-19 18:47 ` Stephen Boyd
[not found] ` <20150619184747.GD22132-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
2015-06-19 18:52 ` Rob Herring
2015-06-19 18:52 ` Rob Herring
[not found] ` <CAL_JsqJfWDO4r_FP6xHSxRkMM-pSnbEUB=d9Gj6mhvPY+ouLxA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-06-20 2:24 ` Viresh Kumar
2015-06-20 2:24 ` Viresh Kumar
2015-06-19 18:44 ` Stephen Boyd
2015-06-19 18:44 ` Stephen Boyd
2015-06-20 2:18 ` Viresh Kumar
2015-06-20 2:18 ` Viresh Kumar
2015-06-04 16:20 ` [PATCH V7 3/3] OPP: Add binding for 'opp-suspend' Viresh Kumar
2015-06-04 16:20 ` Viresh Kumar
2015-06-13 8:40 ` Viresh Kumar
2015-06-13 8:40 ` Viresh Kumar
2015-06-15 22:30 ` Rafael J. Wysocki
2015-06-15 22:30 ` Rafael J. Wysocki
2015-06-15 23:35 ` Rob Herring
2015-06-15 23:35 ` Rob Herring
[not found] ` <CAL_JsqJb4P2Z2esgm5ffjWV37MU2KUF4gBdUpwSV8+21iTD1Bg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-06-16 0:31 ` Viresh Kumar
2015-06-16 0:31 ` Viresh Kumar
2015-06-16 2:54 ` Viresh Kumar
2015-06-16 2:54 ` Viresh Kumar
2015-06-16 19:23 ` Rob Herring
2015-06-16 19:23 ` Rob Herring
2015-06-16 21:21 ` Rafael J. Wysocki
2015-06-16 21:21 ` Rafael J. Wysocki
2015-06-17 2:38 ` Viresh Kumar
2015-06-17 2:38 ` Viresh Kumar
2015-06-17 9:38 ` Rafael J. Wysocki
2015-06-17 9:38 ` Rafael J. Wysocki
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAL_Jsq+SdgAf7=Yq7Jk_1d9jTpAOLCEuEDCZvD=-h=2MWsNfFw@mail.gmail.com' \
--to=robherring2@gmail.com \
--cc=Sudeep.Holla@arm.com \
--cc=arnd.bergmann@linaro.org \
--cc=broonie@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=grant.likely@linaro.org \
--cc=kesavan.abhilash@gmail.com \
--cc=khilman@linaro.org \
--cc=l.stach@pengutronix.de \
--cc=linaro-kernel@lists.linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-pm@vger.kernel.org \
--cc=mike.turquette@linaro.org \
--cc=nm@ti.com \
--cc=olof@lixom.net \
--cc=rjw@rjwysocki.net \
--cc=santosh.shilimkar@oracle.com \
--cc=sboyd@codeaurora.org \
--cc=ta.omasab@gmail.com \
--cc=thomas.petazzoni@free-electrons.com \
--cc=viresh.kumar@linaro.org \
--cc=viswanath.puttagunta@linaro.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.