Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: Kernel panic - not syncing: IO-APIC + timer doesn't work!
To:     Tom Lendacky <thomas.lendacky@amd.com>,
        Thomas Gleixner <tglx@linutronix.de>, bp@alien8.de,
        x86@kernel.org, mingo@redhat.com
Cc:     linux-kernel@vger.kernel.org
References: <18cb4d48-6571-1fdb-5902-ba64c23eee75@broadcom.com>
 <87h7tsbs1n.fsf@nanos.tec.linutronix.de>
 <e0ce41cd-9149-e43e-f4ca-e75503cb82e3@broadcom.com>
 <87blk0aw1k.fsf@nanos.tec.linutronix.de>
 <cc298d3e-9a14-d3e1-025b-6bb1f8bfb4ae@broadcom.com>
 <87y2n2abv2.fsf@nanos.tec.linutronix.de>
 <e41ea714-a042-b29b-d22e-8ee71d23f2e9@amd.com>
From:   Scott Branden <scott.branden@broadcom.com>
Message-ID: <3f6879be-db6e-073d-6252-30d3c046e9e4@broadcom.com>
Date:   Wed, 29 Jul 2020 16:28:00 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <e41ea714-a042-b29b-d22e-8ee71d23f2e9@amd.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Content-Language: en-CA
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Tom,

On 2020-07-29 11:29 a.m., Tom Lendacky wrote:
> On 7/29/20 4:50 AM, Thomas Gleixner wrote:
>> Scott,
>>
>> Scott Branden <scott.branden@broadcom.com> writes:
>>> On 2020-07-28 1:22 a.m., Thomas Gleixner wrote:
>>>> Scott Branden <scott.branden@broadcom.com> writes:
>>>>> Bios now updated to latest.  Same kernel panic issue.  Log below.
>>>>>
>>>>> I think it is related to power cycling quickly.
>>>>> Should APIC work if PC power cycled in a few seconds or is that the
>>>>> problem?
>>>> Yes, emphasis on should. Just to clarify, if you reboot it works and
>>>> cold start works as well if power was off long enough?
>>>>
>>> So far I have only been able to reproduce the issue by cold start with power off for only a few seconds
>>> before re-powering the system.  It has not failed via reboot yet that I remember.
>>> Will have to keep my eye on whether using reboot is an issue or not.
>>> And also keeping power off longer when doing a cold start.
>> Weird.
>>
>>> Please find attached the failed console log with ignore_loglevel.
>> Aside of the differences caused by the BIOS update there is nothing
>> related to the APIC/IO-APIC setup which is different between the working
>> and failing boot.
>>
>> TBH, I have no idea what's going wrong there. Maybe Tom has one.
> I asked around and was told this is most likely the motherboard has not
> decayed its DC rails. So it's quite possible that keeping it powered off
> for a longer period of time before powering back on may help.
It does appear that the APIC hardware or some other component does not reset
something and assumes the power up value is 0.

Too bad proper voltage monitoring/full reset is not in place.

I was just reporting the issue as instructed by the kernel panic.
I think the issue is avoided by leaving the system powered off longer.

> Thanks,
> Tom
>
>> Thanks,
>>
>>         tglx
>>