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Date:   Fri, 25 Feb 2022 14:14:54 +0000
From:   Sudeep Holla <sudeep.holla@arm.com>
To:     Shawn Guo <shawn.guo@linaro.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
Subject: Re: [PATCH] cpuidle: psci: Iterate backwards over list in
 psci_pd_remove()
Message-ID: <20220225141454.uvz4pmlxbalr7zwc@bogus>
References: <20220225082420.450620-1-shawn.guo@linaro.org>
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In-Reply-To: <20220225082420.450620-1-shawn.guo@linaro.org>
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On Fri, Feb 25, 2022 at 04:24:20PM +0800, 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 in a reversely order, so
> that parent PD gets removed before child's PDs.
>

Makes sense.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>

-- 
Regards,
Sudeep