Re: [issue report] pm8001 issues (was driver crashes with IOMMU enabled)

From: John Garry <john.garry@huawei.com>
To: <Ajish.Koshy@microchip.com>, <jinpu.wang@ionos.com>,
	<Viswas.G@microchip.com>
Cc: <linux-scsi@vger.kernel.org>, <vishakhavc@google.com>,
	<ipylypiv@google.com>, <Ruksar.devadi@microchip.com>,
	<damien.lemoal@opensource.wdc.com>,
	<Vasanthalakshmi.Tharmarajan@microchip.com>
Subject: Re: [issue report] pm8001 issues (was driver crashes with IOMMU enabled)
Date: Mon, 10 Jan 2022 20:21:13 +0000	[thread overview]
Message-ID: <34319d65-104d-55a0-175d-96cf3f0aea89@huawei.com> (raw)
In-Reply-To: <PH0PR11MB5112F2D4A506B0FE6DC5B01BEC4D9@PH0PR11MB5112.namprd11.prod.outlook.com>

On 07/01/2022 11:12, Ajish.Koshy@microchip.com wrote:
>> Once the task is dispatched to HW at ****, it is completed async, i.e.
>> it may be completed and freed at any point, even before the dispatch
>> function returns. So it is illegal to touch the task at this point and the task
>> state must be updated before final dispatch to the HW. If you enable KASAN
>> you will prob see it yell like I saw.
>>
> I too have similar thought here. After dispatch to HW, no point to touch the
> task state. But since the code is in IO path, may need further testing.
> 

Hi,

Have you made any progress on the hang which I see on my arm64 system?

I think that you said that you can also see it on an arm64 system - 
would that be with a similar card to mine? I think mine is 8008/9

I have tested some older kernels and v4.11 seems much better.

Thanks,
John