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To: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>, Dave Hansen
 <dave.hansen@intel.com>, mingo@redhat.com, bp@alien8.de,
 dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
 keescook@chromium.org, tony.luck@intel.com, gpiccoli@igalia.com,
 mat.jonczyk@o2.pl, rdunlap@infradead.org, alexandre.belloni@bootlin.com,
 mario.limonciello@amd.com, yaolu@kylinos.cn, bhelgaas@google.com,
 justinstitt@google.com, linux-kernel@vger.kernel.org,
 linux-hardening@vger.kernel.org
Cc: CobeChen@zhaoxin.com, TimGuo@zhaoxin.com, LeoLiu-oc@zhaoxin.com, Linus
 Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH] x86/hpet: Read HPET directly if panic in progress
In-Reply-To: <199ba55d-8eb8-47df-9f42-55a865b51ab7@zhaoxin.com>
References: <20240528063836.5248-1-TonyWWang-oc@zhaoxin.com>
 <50fc1bd3-909e-41c4-a991-9d81e32ef92c@intel.com> <87wmnda8mc.ffs@tglx>
 <2553dd17-f763-4894-89b7-5f76c03d3a37@zhaoxin.com>
 <199ba55d-8eb8-47df-9f42-55a865b51ab7@zhaoxin.com>
Date: Wed, 29 May 2024 09:45:22 +0200
Message-ID: <87fru19i3x.ffs@tglx>
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On Wed, May 29 2024 at 14:44, Tony W Wang-oc wrote:
> Actually, this scenario is what this patch is trying to solve.
>
> We encountered hpet_lock deadlock from the call path of the MCE handler,
> and this hpet_lock deadlock scenario may happen when others exceptions'
> handler like #PF/#GP... to call the panic. So read_hpet should avoid
> deadlock if panic in progress.

That's not what your changelog says.