[Skiboot] [PATCH v7 08/22] hdata: Add support for early OPAL crash

[Nicholas Piggin]

Vasant Hegde's on May 18, 2019 8:34 pm:
> On 05/16/2019 10:38 AM, Nicholas Piggin wrote:
>> Vasant Hegde's on May 14, 2019 9:33 pm:
>>> On 05/09/2019 10:59 AM, Nicholas Piggin wrote:
>>>> Vasant Hegde's on April 13, 2019 7:15 pm:
>>>>> Lets hardcode few entries in MDST and MDDT table.. so that we can capture
>>>>> early OPAL crash. Note that we will have 1 to 1 mapping between MDST and
>>>>> MDDT table entry.
>>>>
>>>> How useful is this? It could be useful if:
>>>> - crash is not reproducable, and
>>>> - customer site where we can't access the BMC, and
>>>> - system eventually boots so crash dump can be saved, and
>>>> - dump is sufficient to debug (i.e., debugging does not involve hardware
>>>>     registers etc).
>>>
>>> Correct.
>>>
>>>>
>>>> I'm a bit skeptical. I reckon we'd get more milage out of changing assert
>>>> to trap so we get regs.
>>>
>>> We do capture registers.. but yes, its useful only when system boots eventually.
>> 
>> I'd like to consider holding off the OPAL crash feature (presumably
>> the Linux dump is significantly more useful and has more moving parts
>> to solve). We should be able to improve boot crashes a lot without
>> this, and then reconsider if it's still wanted.
> 
> You mean early OPAL crashes? Sure. We can defer that.

Yes.

Thanks,
Nick