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Date:   Thu, 22 Jun 2023 11:28:56 -0700 (PDT)
Subject:     Re: (subset) [PATCH V2 0/4] Remove WARN_ON in save_processor_state
In-Reply-To: <168736259084.605458.4732376069158804322.b4-ty@arm.com>
CC:     Will Deacon <will@kernel.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
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        leyfoon.tan@starfivetech.com, mason.huo@starfivetech.com,
        jeeheng.sia@starfivetech.com,
        Conor Dooley <conor.dooley@microchip.com>,
        ajones@ventanamicro.com, songshuaishuai@tinylab.org,
        linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org
From:   Palmer Dabbelt <palmer@dabbelt.com>
To:     Catalin Marinas <catalin.marinas@arm.com>
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On Wed, 21 Jun 2023 08:51:43 PDT (-0700), Catalin Marinas wrote:
> On Fri, 09 Jun 2023 15:50:45 +0800, Song Shuai wrote:
>> During hibernation or restoration, freeze_secondary_cpus
>> checks num_online_cpus via BUG_ON, and the subsequent
>> save_processor_state also does the checking with WARN_ON.
>>
>> In the case of CONFIG_PM_SLEEP_SMP=n, freeze_secondary_cpus
>> is not defined, but the sole possible condition to disable
>> CONFIG_PM_SLEEP_SMP is !SMP where num_online_cpus is always 1.
>> We also don't have to check it in save_processor_state.
>>
>> [...]
>
> Applied to arm64 (for-next/misc), thanks!
>
> I couldn't tell whether this series would go in as a whole but given
> that the patches are independent, I picked up the arm64 one.
>
> [2/4] arm64: hibernate: remove WARN_ON in save_processor_state
>       https://git.kernel.org/arm64/c/615af0021a61

I was pretty much in the same spot until I saw this, so I'm picking the 
RISC-V bit and just ignoring the rest.  It's testing so it might take a bit to
land in linux-next, but seems pretty safe.