Re: [PATCH v3 3/5] OPP: Improve require-opps linking

From: Sibi Sankar <sibis@codeaurora.org>
To: Viresh Kumar <viresh.kumar@linaro.org>,
	Saravana Kannan <saravanak@google.com>
Cc: MyungJoo Ham <myungjoo.ham@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Chanwoo Choi <cw00.choi@samsung.com>,
	Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
	Stephen Boyd <sboyd@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	kernel-team@android.com, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/5] OPP: Improve require-opps linking
Date: Wed, 29 Jan 2020 19:04:44 +0530	[thread overview]
Message-ID: <b0be1275-c5cb-8171-58fa-64d65f60eaf8@codeaurora.org> (raw)
In-Reply-To: <20200127061118.5bxei6nghowlmf53@vireshk-i7>

Hey Viresh,

On 1/27/20 11:41 AM, Viresh Kumar wrote:
> On 25-11-19, 16:58, Viresh Kumar wrote:
>> >From 8df083ca64d82ff57f778689271cc1be75aa99c4 Mon Sep 17 00:00:00 2001
>> Message-Id: <8df083ca64d82ff57f778689271cc1be75aa99c4.1574681211.git.viresh.kumar@linaro.org>
>> From: Viresh Kumar <viresh.kumar@linaro.org>
>> Date: Mon, 25 Nov 2019 13:57:58 +0530
>> Subject: [PATCH] opp: Allow lazy-linking of required-opps
>>
>> The OPP core currently requires the required opp tables to be available
>> before the dependent OPP table is added, as it needs to create links
>> from the dependent OPP table to the required ones. This may not be
>> convenient to all the platforms though, as this requires strict ordering
>> of probing of drivers.
>>
>> This patch allows lazy-linking of the required-opps. The OPP tables for
>> which the required-opp-tables aren't available at the time of their
>> initialization, are added to a special list of OPP tables:
>> pending_opp_tables. Later on, whenever a new OPP table is registered
>> with the OPP core, we check if it is required by an OPP table in the
>> pending list; if yes, then we complete the linking then and there.
>>
>> An OPP table is marked unusable until the time all its required-opp
>> tables are available. And if lazy-linking fails for an OPP table, the
>> OPP core disables all of its OPPs to make sure no one can use them.
>>
>> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>> ---
>>   drivers/opp/core.c |  13 ++++++
>>   drivers/opp/of.c   | 113 +++++++++++++++++++++++++++++++++++++++++++--
>>   drivers/opp/opp.h  |   4 +-
>>   3 files changed, 124 insertions(+), 6 deletions(-)
> 
> I was hoping to queue this up for next release, any update on getting
> this tested ?

I don't have a gen-pd use case to test against but with the is_genpd
check removed it works as expected when I used it against this
series: https://patchwork.kernel.org/cover/11353185/

In the lazy_link_required_opps fn shouldn't we skip the dynamic
opps in the the opp list?

With ^^ addressed:
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Tested-by: Sibi Sankar <sibis@codeaurora.org>

> 
> 

-- 
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc, is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project