From: Sudeep Holla <sudeep.holla@arm.com>
To: Wing Li <wingers@google.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
Maulik Shah <quic_mkshah@quicinc.com>,
andersson@kernel.org, dianders@chromium.org, swboyd@chromium.org,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-pm@vger.kernel.org, jwerner@chromium.org,
quic_lsrao@quicinc.com, quic_rjendra@quicinc.com
Subject: Re: [PATCH v2 1/2] cpuidle: psci: Move enabling OSI mode after power domains creation
Date: Fri, 31 Mar 2023 15:27:24 +0100 [thread overview]
Message-ID: <20230331142724.ogvruad7txfe7ji2@bogus> (raw)
In-Reply-To: <CADut4F3UmMXCYHeE6sXfoJtgEp36Fv65Poe1Z0JKT0DETyaowQ@mail.gmail.com>
On Thu, Mar 30, 2023 at 06:40:03PM -0700, Wing Li wrote:
> Adding some clarifications.
>
> On Thu, Mar 30, 2023 at 6:13 AM Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> > On Thu, Mar 30, 2023 at 02:06:19PM +0200, Ulf Hansson wrote:
> > > On Thu, 30 Mar 2023 at 11:34, Sudeep Holla <sudeep.holla@arm.com> wrote:
> > > >
> > > > On Thu, Mar 30, 2023 at 02:12:49PM +0530, Maulik Shah wrote:
> > > > > A switch from OSI to PC mode is only possible if all CPUs other than
> > the
> > > > > calling one are OFF, either through a call to CPU_OFF or not yet
> > booted.
> > > > >
> > > >
> > > > As per the spec, all cores are in one of the following states:
> > > > - Running
> > > > - OFF, either through a call to CPU_OFF or not yet booted
> > > > - Suspended, through a call to CPU_DEFAULT_SUSPEND
> > > >
> > > > Better to provide full information.
> >
>
> The spec quoted above only applies when switching from platform-coordinated
> mode to OS-initiated mode.
>
> For switching from OS-initiated to platform-coordinated, which is the case
> Maulik is referring to, section 5.20.2 of the spec specifies:
> "A switch from OS-initiated mode to platform-coordinated mode is only
> possible if all cores other than the calling one are OFF, either through a
> call to CPU_OFF or not yet booted."
>
>
My bad, I read/imagined it as PC->OSI mode couple of times even though it
is pretty explicit. Sorry for that. And thanks a lot for pointing that out.
--
Regards,
Sudeep
next prev parent reply other threads:[~2023-03-31 14:36 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-30 8:42 [PATCH v2 0/2] Use PSCI OS initiated mode for sc7280 Maulik Shah
2023-03-30 8:42 ` [PATCH v2 1/2] cpuidle: psci: Move enabling OSI mode after power domains creation Maulik Shah
2023-03-30 9:34 ` Sudeep Holla
2023-03-30 12:06 ` Ulf Hansson
2023-03-30 13:13 ` Sudeep Holla
2023-03-31 1:46 ` Wing Li
[not found] ` <CADut4F3UmMXCYHeE6sXfoJtgEp36Fv65Poe1Z0JKT0DETyaowQ@mail.gmail.com>
2023-03-31 14:27 ` Sudeep Holla [this message]
2023-03-30 12:19 ` Ulf Hansson
2023-03-30 8:42 ` [PATCH v2 2/2] arm64: dts: qcom: sc7280: Add power-domains for cpuidle states Maulik Shah
2023-03-30 12:21 ` Ulf Hansson
2023-03-30 9:38 ` [PATCH v2 0/2] Use PSCI OS initiated mode for sc7280 Sudeep Holla
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