MIME-Version: 1.0
References: <20220308082931.3385902-1-shawn.guo@linaro.org> <7da47edd-60ba-d8fc-9d30-4dc0e5969bb2@somainline.org>
In-Reply-To: <7da47edd-60ba-d8fc-9d30-4dc0e5969bb2@somainline.org>
From:   Shawn Guo <shawn.guo@linaro.org>
Date:   Fri, 3 Mar 2023 08:37:52 +0800
Message-ID: <CAAQ0ZWTx9HpWHwrOryCTtXWAwktkAtSANCk6iVVzas8116=ZYg@mail.gmail.com>
Subject: Re: [PATCH v2] cpuidle: psci: Iterate backwards over list in psci_pd_remove()
To:     Konrad Dybcio <konrad.dybcio@somainline.org>
Cc:     Daniel Lezcano <daniel.lezcano@linaro.org>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Ulf Hansson <ulf.hansson@linaro.org>, linux-pm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Thu, Mar 2, 2023 at 10:46 PM Konrad Dybcio
<konrad.dybcio@somainline.org> wrote:
>
>
>
> On 8.03.2022 09:29, Shawn Guo wrote:
> > In case that psci_pd_init_topology() fails for some reason,
> > psci_pd_remove() will be responsible for deleting provider and removing
> > genpd from psci_pd_providers list.  There will be a failure when removing
> > the cluster PD, because the cpu (child) PDs haven't been removed.
> >
> > [    0.050232] CPUidle PSCI: init PM domain cpu0
> > [    0.050278] CPUidle PSCI: init PM domain cpu1
> > [    0.050329] CPUidle PSCI: init PM domain cpu2
> > [    0.050370] CPUidle PSCI: init PM domain cpu3
> > [    0.050422] CPUidle PSCI: init PM domain cpu-cluster0
> > [    0.050475] PM: genpd_remove: unable to remove cpu-cluster0
> > [    0.051412] PM: genpd_remove: removed cpu3
> > [    0.051449] PM: genpd_remove: removed cpu2
> > [    0.051499] PM: genpd_remove: removed cpu1
> > [    0.051546] PM: genpd_remove: removed cpu0
> >
> > Fix the problem by iterating the provider list reversely, so that parent
> > PD gets removed after child's PDs like below.
> >
> > [    0.029052] CPUidle PSCI: init PM domain cpu0
> > [    0.029076] CPUidle PSCI: init PM domain cpu1
> > [    0.029103] CPUidle PSCI: init PM domain cpu2
> > [    0.029124] CPUidle PSCI: init PM domain cpu3
> > [    0.029151] CPUidle PSCI: init PM domain cpu-cluster0
> > [    0.029647] PM: genpd_remove: removed cpu0
> > [    0.029666] PM: genpd_remove: removed cpu1
> > [    0.029690] PM: genpd_remove: removed cpu2
> > [    0.029714] PM: genpd_remove: removed cpu3
> > [    0.029738] PM: genpd_remove: removed cpu-cluster0
> >
> > Fixes: a65a397f2451 ("cpuidle: psci: Add support for PM domains by using genpd")
> > Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
> > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
> > Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> > ---
> Looks like this was never picked up or followed up on?

Oops!  I thought it was already applied.  I will ping Rafael with a resend.

Shawn