From: Georgi Djakov <georgi.djakov@linaro.org>
To: Greg KH <gregkh@linuxfoundation.org>, Evan Green <evgreen@chromium.org>
Cc: linux-pm@vger.kernel.org, rjw@rjwysocki.net, robh+dt@kernel.org,
Michael Turquette <mturquette@baylibre.com>,
khilman@baylibre.com,
Vincent Guittot <vincent.guittot@linaro.org>,
Saravana Kannan <skannan@codeaurora.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
amit.kucheria@linaro.org, seansw@qti.qualcomm.com,
daidavid1@codeaurora.org, mark.rutland@arm.com,
lorenzo.pieralisi@arm.com,
Alexandre Bailon <abailon@baylibre.com>,
maxime.ripard@bootlin.com, Arnd Bergmann <arnd@arndb.de>,
Thierry Reding <thierry.reding@gmail.com>,
ksitaraman@nvidia.com, sanjayc@nvidia.com,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org, linux-tegra@vger.kernel.org,
Doug Anderson <dianders@chromium.org>
Subject: Re: [PATCH v10 0/8] Introduce on-chip interconnect API
Date: Fri, 7 Dec 2018 12:06:21 +0200 [thread overview]
Message-ID: <bdc4bad1-d613-4144-2e5b-2657e170affa@linaro.org> (raw)
In-Reply-To: <20181206145547.GA7884@kroah.com>
Hi Greg and Evan,
On 12/6/18 16:55, Greg KH wrote:
> On Wed, Dec 05, 2018 at 12:41:35PM -0800, Evan Green wrote:
>> On Tue, Nov 27, 2018 at 10:03 AM Georgi Djakov <georgi.djakov@linaro.org> wrote:
>>>
>>> Modern SoCs have multiple processors and various dedicated cores (video, gpu,
>>> graphics, modem). These cores are talking to each other and can generate a
>>> lot of data flowing through the on-chip interconnects. These interconnect
>>> buses could form different topologies such as crossbar, point to point buses,
>>> hierarchical buses or use the network-on-chip concept.
>>>
>>> These buses have been sized usually to handle use cases with high data
>>> throughput but it is not necessary all the time and consume a lot of power.
>>> Furthermore, the priority between masters can vary depending on the running
>>> use case like video playback or CPU intensive tasks.
>>>
>>> Having an API to control the requirement of the system in terms of bandwidth
>>> and QoS, so we can adapt the interconnect configuration to match those by
>>> scaling the frequencies, setting link priority and tuning QoS parameters.
>>> This configuration can be a static, one-time operation done at boot for some
>>> platforms or a dynamic set of operations that happen at run-time.
>>>
>>> This patchset introduce a new API to get the requirement and configure the
>>> interconnect buses across the entire chipset to fit with the current demand.
>>> The API is NOT for changing the performance of the endpoint devices, but only
>>> the interconnect path in between them.
>>
>> For what it's worth, we are ready to land this in Chrome OS. I think
>> this series has been very well discussed and reviewed, hasn't changed
>> much in the last few spins, and is in good enough shape to use as a
>> base for future patches. Georgi's also done a great job reaching out
>> to other SoC vendors, and there appears to be enough consensus that
>> this framework will be usable by more than just Qualcomm. There are
>> also several drivers out on the list trying to add patches to use this
>> framework, with more to come, so it made sense (to us) to get this
>> base framework nailed down. In my experiments this is an important
>> piece of the overall power management story, especially on systems
>> that are mostly idle.
>>
>> I'll continue to track changes to this series and we will ultimately
>> reconcile with whatever happens upstream, but I thought it was worth
>> sending this note to express our "thumbs up" towards this framework.
>
> Looks like a v11 will be forthcoming, so I'll wait for that one to apply
> it to the tree if all looks good.
>
Yes, it's coming. I will also include an additional fixup patch, as the
sdm845 provider driver will fail to build in linux-next, due to a recent
change in the cmd_db API.
Thanks,
Georgi
next prev parent reply other threads:[~2018-12-07 10:06 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-27 18:03 [PATCH v10 0/8] Introduce on-chip interconnect API Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 1/7] interconnect: Add generic " Georgi Djakov
2018-11-27 18:35 ` Joe Perches
2018-11-28 18:18 ` Georgi Djakov
2018-12-01 0:38 ` Evan Green
2018-12-05 15:57 ` Georgi Djakov
2018-12-05 16:16 ` Rob Herring
2018-12-07 15:24 ` Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 2/7] dt-bindings: Introduce interconnect binding Georgi Djakov
2018-12-01 0:38 ` Evan Green
2018-11-27 18:03 ` [PATCH v10 3/7] interconnect: Allow endpoints translation via DT Georgi Djakov
2018-12-01 0:38 ` Evan Green
2018-12-05 15:59 ` Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 4/7] interconnect: Add debugfs support Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 5/7] interconnect: qcom: Add sdm845 interconnect provider driver Georgi Djakov
2018-12-01 0:39 ` Evan Green
2018-12-05 16:00 ` Georgi Djakov
2018-12-06 21:53 ` David Dai
2018-11-27 18:03 ` [PATCH v10 6/7] arm64: dts: sdm845: Add interconnect provider DT nodes Georgi Djakov
2018-12-01 0:39 ` Evan Green
2018-12-05 16:01 ` Georgi Djakov
2018-11-27 18:03 ` [PATCH v10 7/7] MAINTAINERS: add a maintainer for the interconnect API Georgi Djakov
2018-12-05 20:41 ` [PATCH v10 0/8] Introduce on-chip " Evan Green
2018-12-06 14:55 ` Greg KH
2018-12-07 10:06 ` Georgi Djakov [this message]
2018-12-10 9:04 ` Rafael J. Wysocki
2018-12-10 10:18 ` Georgi Djakov
2018-12-10 11:00 ` Rafael J. Wysocki
2018-12-10 14:50 ` Georgi Djakov
2018-12-11 6:58 ` Greg Kroah-Hartman
2018-12-17 11:17 ` Georgi Djakov
2019-01-10 14:19 ` Georgi Djakov
2019-01-10 16:29 ` Greg Kroah-Hartman
2019-01-10 16:34 ` Georgi Djakov
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