Re: [PATCH v6 0/3] Introduce Bandwidth OPPs for interconnects

From: Viresh Kumar <viresh.kumar@linaro.org>
To: Saravana Kannan <saravanak@google.com>
Cc: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
	Stephen Boyd <sboyd@kernel.org>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Georgi Djakov <georgi.djakov@linaro.org>,
	vincent.guittot@linaro.org, seansw@qti.qualcomm.com,
	daidavid1@codeaurora.org, adharmap@codeaurora.org,
	Rajendra Nayak <rnayak@codeaurora.org>,
	sibis@codeaurora.org, bjorn.andersson@linaro.org,
	evgreen@chromium.org, kernel-team@android.com,
	linux-pm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 0/3] Introduce Bandwidth OPPs for interconnects
Date: Tue, 14 Jan 2020 16:04:48 +0530	[thread overview]
Message-ID: <20200114103448.odnvqawnqb3twst5@vireshk-i7> (raw)
In-Reply-To: <20191207002424.201796-1-saravanak@google.com>

On 06-12-19, 16:24, Saravana Kannan wrote:
> gpu_cache_opp_table: gpu_cache_opp_table {
> 	compatible = "operating-points-v2";
> 
> 	gpu_cache_3000: opp-3000 {
> 		opp-peak-KBps = <3000000>;
> 		opp-avg-KBps = <1000000>;
> 	};
> 	gpu_cache_6000: opp-6000 {
> 		opp-peak-KBps = <6000000>;
> 		opp-avg-KBps = <2000000>;
> 	};
> 	gpu_cache_9000: opp-9000 {
> 		opp-peak-KBps = <9000000>;
> 		opp-avg-KBps = <9000000>;
> 	};
> };
> 
> gpu_ddr_opp_table: gpu_ddr_opp_table {
> 	compatible = "operating-points-v2";
> 
> 	gpu_ddr_1525: opp-1525 {
> 		opp-peak-KBps = <1525000>;
> 		opp-avg-KBps = <452000>;
> 	};
> 	gpu_ddr_3051: opp-3051 {
> 		opp-peak-KBps = <3051000>;
> 		opp-avg-KBps = <915000>;
> 	};
> 	gpu_ddr_7500: opp-7500 {
> 		opp-peak-KBps = <7500000>;
> 		opp-avg-KBps = <3000000>;
> 	};
> };
> 
> gpu_opp_table: gpu_opp_table {
> 	compatible = "operating-points-v2";
> 	opp-shared;
> 
> 	opp-200000000 {
> 		opp-hz = /bits/ 64 <200000000>;
> 	};
> 	opp-400000000 {
> 		opp-hz = /bits/ 64 <400000000>;
> 	};
> };
> 
> gpu@7864000 {
> 	...
> 	operating-points-v2 = <&gpu_opp_table>, <&gpu_cache_opp_table>, <&gpu_ddr_opp_table>;

Okay, I got confused a bit again after some interaction with Sibi
today. The multiple phandle thing in the operating-points-v2 property
is there specifically for nodes that can provide multiple devices,
like PM domains where the provider may end up providing multiple
domains.

But I am not sure what you are going to do with the list of phandles
you have set for the GPU here.

We can not add multiple OPP tables for a single device right now.

-- 
viresh