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

[John Garry <john.garry@huawei.com>]

Hi Ajish,

>>
>>>>    From an earlier mail [0] I got the impression that you tested on an
>>>> arm platform – did you?
>>> Yes, with respect to my previous mail update, at that time got the
>>> chance to load the driver on ARM server/enclosure connected in one of
>>> our tester's arm server after attaching the controller card.
>>> There this error handling issue was observed.
>>>
>>> The card/driver was never tested or validated on ARM server before,
>>> was curious to see the behavior for the first time. Whereas driver
>>> loads smoothly on x86 server.
>>>
>>> Currently busy with some other issues, debugging on ARM server is not
>>> planned for now.
>>>
>> OK, since you do see this same/similar issue with another card on arm then I
>> think that it is safe to assume that it is a driver issue.
>>
>> If you can share the dmesg on the arm machine then at least that would be
>> helpful.
> Right now the arm configuration is not available. Will be difficult
> to get dmesg.

By adding (enabling) a tonne of debug logs in the the driver and 
enabling heavy kernel debug config options mount+umount works reliably. 
So it looks like a timing issue / memory barrier issue - yuck. Since the 
issue is so reliably produced it seems unlikely to be a barrier issue.

There are lots of files in the shost sysfs folder - can any of these be 
used to help debug?

Thanks,
John