From: Viresh Kumar <viresh.kumar@linaro.org>
To: Saravana Kannan <saravanak@google.com>
Cc: Georgi Djakov <georgi.djakov@linaro.org>,
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>,
vincent.guittot@linaro.org, seansw@qti.qualcomm.com,
daidavid1@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 v3 0/6] Introduce Bandwidth OPPs for interconnect paths
Date: Wed, 17 Jul 2019 16:02:20 +0530 [thread overview]
Message-ID: <20190717103220.f7cys267hq23fbsb@vireshk-i7> (raw)
In-Reply-To: <20190703011020.151615-1-saravanak@google.com>
On 02-07-19, 18:10, Saravana Kannan wrote:
> Interconnects and interconnect paths quantify their performance levels in
> terms of bandwidth and not in terms of frequency. So similar to how we have
> frequency based OPP tables in DT and in the OPP framework, we need
> bandwidth OPP table support in the OPP framework and in DT. Since there can
> be more than one interconnect path used by a device, we also need a way to
> assign a bandwidth OPP table to an interconnect path.
>
> This patch series:
> - Adds opp-peak-KBps and opp-avg-KBps properties to OPP DT bindings
> - Adds interconnect-opp-table property to interconnect DT bindings
> - Adds OPP helper functions for bandwidth OPP tables
> - Adds icc_get_opp_table() to get the OPP table for an interconnect path
>
> So with the DT bindings added in this patch series, the DT for a GPU
> that does bandwidth voting from GPU to Cache and GPU to DDR would look
> something like this:
>
> gpu_cache_opp_table: gpu_cache_opp_table {
> compatible = "operating-points-v2";
>
> gpu_cache_3000: opp-3000 {
> opp-peak-KBps = <3000>;
> opp-avg-KBps = <1000>;
> };
> gpu_cache_6000: opp-6000 {
> opp-peak-KBps = <6000>;
> opp-avg-KBps = <2000>;
> };
> gpu_cache_9000: opp-9000 {
> opp-peak-KBps = <9000>;
> opp-avg-KBps = <9000>;
> };
> };
>
> gpu_ddr_opp_table: gpu_ddr_opp_table {
> compatible = "operating-points-v2";
>
> gpu_ddr_1525: opp-1525 {
> opp-peak-KBps = <1525>;
> opp-avg-KBps = <452>;
> };
> gpu_ddr_3051: opp-3051 {
> opp-peak-KBps = <3051>;
> opp-avg-KBps = <915>;
> };
> gpu_ddr_7500: opp-7500 {
> opp-peak-KBps = <7500>;
> opp-avg-KBps = <3000>;
> };
> };
Who is going to use the above tables and how ? These are the maximum
BW available over these paths, right ?
> 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>;
> };
> };
Shouldn't this link back to the above tables via required-opp, etc ?
How will we know how much BW is required by the GPU device for all the
paths ?
> gpu@7864000 {
> ...
> operating-points-v2 = <&gpu_opp_table>, <&gpu_cache_opp_table>, <&gpu_ddr_opp_table>;
> interconnects = <&mmnoc MASTER_GPU_1 &bimc SLAVE_SYSTEM_CACHE>,
> <&mmnoc MASTER_GPU_1 &bimc SLAVE_DDR>;
> interconnect-names = "gpu-cache", "gpu-mem";
> interconnect-opp-table = <&gpu_cache_opp_table>, <&gpu_ddr_opp_table>
> };
--
viresh
next prev parent reply other threads:[~2019-07-17 10:32 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-03 1:10 [PATCH v3 0/6] Introduce Bandwidth OPPs for interconnect paths Saravana Kannan
2019-07-03 1:10 ` [PATCH v3 1/6] dt-bindings: opp: Introduce opp-peak-KBps and opp-avg-KBps bindings Saravana Kannan
2019-07-16 17:25 ` Sibi Sankar
2019-07-16 18:58 ` Saravana Kannan
2019-07-22 23:35 ` Rob Herring
2019-07-22 23:40 ` Saravana Kannan
2019-07-23 14:26 ` Rob Herring
2019-07-24 0:18 ` Saravana Kannan
2019-07-17 7:54 ` Viresh Kumar
2019-07-17 20:29 ` Saravana Kannan
2019-07-18 4:35 ` Viresh Kumar
2019-07-18 17:26 ` Saravana Kannan
2019-07-26 16:24 ` Georgi Djakov
2019-07-26 19:08 ` Saravana Kannan
2019-07-03 1:10 ` [PATCH v3 2/6] OPP: Add support for bandwidth OPP tables Saravana Kannan
2019-07-16 17:33 ` Sibi Sankar
2019-07-16 19:10 ` Saravana Kannan
2019-07-30 10:57 ` Amit Kucheria
2019-07-30 23:20 ` Saravana Kannan
2019-07-03 1:10 ` [PATCH v3 3/6] OPP: Add helper function " Saravana Kannan
2019-07-03 1:10 ` [PATCH v3 4/6] OPP: Add API to find an OPP table from its DT node Saravana Kannan
2019-07-03 1:10 ` [PATCH v3 5/6] dt-bindings: interconnect: Add interconnect-opp-table property Saravana Kannan
2019-07-22 23:39 ` Rob Herring
2019-07-22 23:43 ` Saravana Kannan
2019-07-23 2:21 ` Viresh Kumar
2019-07-03 1:10 ` [PATCH v3 6/6] interconnect: Add OPP table support for interconnects Saravana Kannan
2019-07-03 6:45 ` Vincent Guittot
2019-07-03 21:33 ` Saravana Kannan
2019-07-04 7:12 ` Vincent Guittot
2019-07-07 21:48 ` Saravana Kannan
2019-07-09 7:25 ` Vincent Guittot
2019-07-09 19:02 ` Saravana Kannan
2019-07-15 8:16 ` Vincent Guittot
2019-07-16 0:55 ` Saravana Kannan
2019-07-24 7:16 ` Vincent Guittot
2019-07-26 16:25 ` Georgi Djakov
2019-07-26 19:08 ` Saravana Kannan
2019-07-03 6:36 ` [PATCH v3 0/6] Introduce Bandwidth OPPs for interconnect paths Viresh Kumar
2019-07-03 20:35 ` Saravana Kannan
2019-07-17 10:32 ` Viresh Kumar [this message]
2019-07-17 20:34 ` Saravana Kannan
2019-07-18 5:37 ` Viresh Kumar
2019-07-19 4:12 ` Saravana Kannan
2019-07-29 9:24 ` Viresh Kumar
2019-07-29 20:12 ` Saravana Kannan
2019-07-30 3:01 ` Viresh Kumar
2019-08-03 1:20 ` Saravana Kannan
2019-08-03 7:36 ` Saravana Kannan
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