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From: Jens Axboe <axboe@kernel.dk>
To: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	Len Brown <lenb@kernel.org>,
	linux-pm@vger.kernel.org
Subject: Re: Bug: d0e936adbd22 crashes at boot
Date: Fri, 3 Sep 2021 14:57:24 -0600	[thread overview]
Message-ID: <a6041178-e7d6-4ad9-b96a-91b4702d0305@kernel.dk> (raw)
In-Reply-To: <903f2e71-983f-39b8-dd0b-d697616ab63e@kernel.dk>

On 9/3/21 2:41 PM, Jens Axboe wrote:
> On 9/3/21 12:00 PM, Srinivas Pandruvada wrote:
>> Hi Axobe,
>>
>> On Fri, 2021-09-03 at 09:00 -0600, Jens Axboe wrote:
>>> On 9/3/21 8:38 AM, Srinivas Pandruvada wrote:
>>>> On Fri, 2021-09-03 at 08:15 -0600, Jens Axboe wrote:
>>>>> On 9/3/21 8:13 AM, Srinivas Pandruvada wrote:
>>>>>> Hi Axboe,
>>>>>>
>>>>>> Thanks for reporting.
>>>>>> On Fri, 2021-09-03 at 07:36 -0600, Jens Axboe wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> Booting Linus's tree causes a crash on my laptop, an x1 gen9.
>>>>>>> This
>>>>>>> was
>>>>>>> a bit
>>>>>>> difficult to pin down as it crashes before the display is up,
>>>>>>> but I
>>>>>>> managed
>>>>>>> to narrow it down to:
>>>>>>>
>>>>>>> commit d0e936adbd2250cb03f2e840c6651d18edc22ace
>>>>>>> Author: Srinivas Pandruvada < 
>>>>>>> srinivas.pandruvada@linux.intel.com>
>>>>>>> Date:   Thu Aug 19 19:40:06 2021 -0700
>>>>>>>
>>>>>>>     cpufreq: intel_pstate: Process HWP Guaranteed change
>>>>>>> notification
>>>>>>>
>>>>>>> which crashes with a NULL pointer deref in
>>>>>>> notify_hwp_interrupt() -
>>>>>>>>
>>>>>>> queue_delayed_work_on().
>>>>>>>
>>>>>>> Reverting this change makes the laptop boot fine again.
>>>>>>>
>>>>>> Does this change fixes your issue?
>>>>>
>>>>> I would assume so, as it's crashing on cpudata == NULL :-)
>>>>>
>>>>> But why is it NULL? Happy to test patches, but the below doesn't
>>>>> look
>>>>> like
>>>>> a real fix and more of a work-around.
>>>>
>>
>> Please try the attached.
> 
> I'll give it a test spin right now. Please do add a Reported-by tag,
> though. That's always prudent.

And you can add Tested-by as well, it works for me.

-- 
Jens Axboe


  reply	other threads:[~2021-09-03 20:57 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-03 13:36 Bug: d0e936adbd22 crashes at boot Jens Axboe
2021-09-03 14:13 ` Srinivas Pandruvada
2021-09-03 14:15   ` Jens Axboe
2021-09-03 14:38     ` Srinivas Pandruvada
2021-09-03 15:00       ` Jens Axboe
2021-09-03 15:11         ` Srinivas Pandruvada
2021-09-03 18:00         ` Srinivas Pandruvada
2021-09-03 20:41           ` Jens Axboe
2021-09-03 20:57             ` Jens Axboe [this message]
2021-09-03 22:38               ` Srinivas Pandruvada

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