From: Borislav Petkov <bp@alien8.de>
To: Rong Zhang <i@rong.moe>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Mario Limonciello <mario.limonciello@amd.com>,
Yazen Ghannam <yazen.ghannam@amd.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/CPU/AMD: Prevent reset reasons from being retained among boots
Date: Tue, 16 Sep 2025 16:02:27 +0200 [thread overview]
Message-ID: <20250916140227.GGaMlt8xSp3eMI8Veu@fat_crate.local> (raw)
In-Reply-To: <20250913144245.23237-1-i@rong.moe>
On Sat, Sep 13, 2025 at 10:42:45PM +0800, Rong Zhang wrote:
> The S5_RESET_STATUS register is parsed on boot and printed to kmsg.
> However, this could sometimes be misleading and lead to users wasting a
> lot of time on meaningless debugging for two reasons:
>
> * Some bits are never cleared by hardware. It's the software's
> responsibility to clear them as per the Processor Programming Reference
> (see Link:).
>
> * Some rare hardware-initiated platform resets do not update the
> register at all.
>
> In both cases, a previous reboot could leave its trace in the register,
> resulting in users seeing unrelated reboot reasons while debugging
> random reboots afterward.
Just a heads-up: we're figuring out internally what the right thing to do here
would be.
Stay tuned.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2025-09-16 14:02 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-13 14:42 Rong Zhang
2025-09-16 14:02 ` Borislav Petkov [this message]
2025-09-29 4:01 ` Mario Limonciello (AMD) (kernel.org)
2025-09-30 10:18 ` Rong Zhang
2025-10-06 13:31 ` Borislav Petkov
2025-10-06 17:07 ` Rong Zhang
2025-10-06 21:41 ` Borislav Petkov
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