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Date:   Thu, 27 Jul 2023 08:30:39 +0530
From:   Pavan Kondeti <quic_pkondeti@quicinc.com>
To:     Elliot Berman <quic_eberman@quicinc.com>
CC:     Pavan Kondeti <quic_pkondeti@quicinc.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        "Sebastian Reichel" <sre@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        "Rob Herring" <robh+dt@kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <linux-pm@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <kernel@quicinc.com>,
        Satya Durga Srinivasu Prabhala <quic_satyap@quicinc.com>,
        Melody Olvera <quic_molvera@quicinc.com>,
        "Prasad Sodagudi" <quic_psodagud@quicinc.com>
Subject: Re: [RFC PATCH 4/4] power: reset: Implement a PSCI SYSTEM_RESET2
 reboot-mode driver
Message-ID: <c1c2653e-4f3b-45f2-9325-d0ed8572a346@quicinc.com>
References: <20230724223057.1208122-1-quic_eberman@quicinc.com>
 <20230724223057.1208122-5-quic_eberman@quicinc.com>
 <46744a2e-139c-4e4e-89b2-66346f64c3f2@quicinc.com>
 <6a0ea31d-814b-6745-d301-c1f6dadf9718@quicinc.com>
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On Wed, Jul 26, 2023 at 10:19:01AM -0700, Elliot Berman wrote:
> 
> 
> On 7/26/2023 3:41 AM, Pavan Kondeti wrote:
> > On Mon, Jul 24, 2023 at 03:30:54PM -0700, Elliot Berman wrote:
> > > PSCI implements a restart notifier for architectural defined resets.
> > > The SYSTEM_RESET2 allows vendor firmware to define additional reset
> > > types which could be mapped to the reboot reason.
> > > 
> > > Implement a driver to wire the reboot-mode framework to make vendor
> > > SYSTEM_RESET2 calls on reboot.
> > > 
> > > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> > 
> > Do we need to skip the PSCI call from the existing PSCI restart notifier
> > which gets called after your newly introduced callback from reboot mode
> > notifier?
> > 
> 
> No need, the vendor SYSTEM_RESET2 call shouldn't return if the call worked.
> 

From the documentation of restart handlers, restarting from reboot
notifiers may not be correct. Since you hooked it up with reboot-mode
driver framework, you may restart the system much early before the
actual machine restart kicks in. Pls check. 

Thanks,
Pavan