From: Matthias Kaehlcke <mka@chromium.org>
To: Rajendra Nayak <quic_rjendra@quicinc.com>
Cc: agross@kernel.org, andersson@kernel.org,
konrad.dybcio@somainline.org, robh+dt@kernel.org,
krzysztof.kozlowski+dt@linaro.org, linux-arm-msm@vger.kernel.org,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
sboyd@kernel.org, johan+linaro@kernel.org,
quic_kriskura@quicinc.com, dianders@chromium.org
Subject: Re: [Patch v2] arm64: dts: qcom: sc7280: Add required-opps for USB
Date: Fri, 16 Sep 2022 12:42:00 +0000 [thread overview]
Message-ID: <YyRvGDm2agpEI5zg@google.com> (raw)
In-Reply-To: <20220916103124.30581-1-quic_rjendra@quicinc.com>
On Fri, Sep 16, 2022 at 04:01:24PM +0530, Rajendra Nayak wrote:
> USB has a requirement to put a performance state vote on 'cx'
> while active. Use 'required-opps' to pass this information from
> device tree, and since all the GDSCs in GCC (including USB) are
> sub-domains of cx, we also add cx as a power-domain for GCC.
> Now when any of the consumers of the GDSCs (in this case USB)
> votes on a perforamance state, genpd framework can identify that
> the GDSC itself does not support a performance state and it
> then propogates the vote to the parent, which in this case is cx.
>
> This change would also mean that any GDSC in GCC thats left enabled
> during low power state (perhaps because its marked with a
> ALWAYS_ON flag) can prevent the system from entering low power
> since that would prevent cx from transitioning to low power.
> Ideally any consumers that would need to have their devices
> (partially) powered to support wakeups should look at making the
> resp. GDSCs transtion to a Retention (PWRSTS_RET) state instead
> of leaving them ALWAYS_ON.
>
> Signed-off-by: Rajendra Nayak <quic_rjendra@quicinc.com>
I suppose a similar patch is needed for sc7180?
prev parent reply other threads:[~2022-09-16 12:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-16 10:31 [Patch v2] arm64: dts: qcom: sc7280: Add required-opps for USB Rajendra Nayak
2022-09-16 12:42 ` Matthias Kaehlcke [this message]
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=YyRvGDm2agpEI5zg@google.com \
--to=mka@chromium.org \
--cc=agross@kernel.org \
--cc=andersson@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=dianders@chromium.org \
--cc=johan+linaro@kernel.org \
--cc=konrad.dybcio@somainline.org \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=quic_kriskura@quicinc.com \
--cc=quic_rjendra@quicinc.com \
--cc=robh+dt@kernel.org \
--cc=sboyd@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).