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From: Thomas Gleixner <tglx@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>, Sneh Mankad
 <sneh.mankad@oss.qualcomm.com>
Cc: Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>, Peter Zijlstra
 <peterz@infradead.org>, "Rafael J. Wysocki" <rafael@kernel.org>, Pavel
 Machek <pavel@kernel.org>, Len Brown <lenb@kernel.org>, Catalin Marinas
 <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>,
 linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2] arm64: Disallow disabling boot CPU based on config
In-Reply-To: <akfHIH_dZrr5bosu@J2N7QTR9R3>
References: <20260703-disable_boot_cpu_offline-v2-1-782d16ff58c3@oss.qualcomm.com>
 <akfHIH_dZrr5bosu@J2N7QTR9R3>
Date: Fri, 03 Jul 2026 23:09:34 +0200
Message-ID: <878q7rlr01.ffs@fw13>
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On Fri, Jul 03 2026 at 15:28, Mark Rutland wrote:
> On Fri, Jul 03, 2026 at 04:50:02PM +0530, Sneh Mankad wrote:
>> +       depends on HOTPLUG_CPU
>> +       depends on SUSPEND
>> +       help
>> +         Disallow boot CPU (CPU0) offline when the suspend_ops->enter()
>> +         has to be executed by boot CPU.
>
> As above, I don't think this makse sense as a config option.

Correct. That's pointless as it can be determined at boot time either
through firmware (ACPI/DT) or if that's not possible for whatever
reasons then a runtime detection quirk which depends on that particular
platform.