Re: [PATCH 1/4] scsi: libsas: Add sas_execute_internal_abort_single()

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

On 25/04/2022 09:34, Hannes Reinecke wrote:
>>>> +/* LLDDs rely on these values */
>>>> +enum sas_internal_abort {
>>>> +    SAS_INTERNAL_ABORT_SINGLE    = 0,
>>>> +};
>>>> +
>>>
>>> Why don't you use the existing TMF_XXX values here?
>>> Your 'single' method pretty much _is_ a TMF_ABORT_TASK, and the 
>>> 'device' method _is_ a TMF_ABORT_TASK_SET, no?
>>
>> Sure, they are doing the same as TMFs and there is equivalence in the 
>> 'single' and 'device' methods, as you say.
>>
>> However, as mentioned in the comment, the LLDDs rely on the values in 
>> enum sas_internal_abort, which do not match the values in 
>> TMF_ABORT{_TASK, _TASK_SET}.
>>
> How can they rely on a value which you just introduced?

I am relying on no one changing those values in enum sas_internal_abort.

Both hisi_sas and pm8001 use value of 0 for single abort and 1 for 
device abort in their own internal abort HW frames structs.

And if some other controller comes along which wants to support this 
feature and the values in enum sas_internal_abort don't match then they 
would need to do some translation.

I could use TMF values and do the translation in hisi_sas and pm8001 
drivers today, but I don't see much much gain in that.

Thanks,
John