Re: [PATCH v1] bbdev: allow operation type enum for growth

[Ray Kinsella <mdr@ashroe.eu>]

Thomas Monjalon <thomas@monjalon.net> writes:

> This solution is what I proposed to the techboard some years ago,
> but the preference was to completely remove the MAX values.


I am mindful we don't have an explicit guidance in the documentation.
I am including to add something to the abi_versioning document, that
basically says

1. Try not to use _MAX values with enumerations.
2. If you have to use _MAX values with enumeration, consider giving
yourself some headroom along with rigourous checking?

>
>
> 13/06/2022 20:24, Nicolas Chautru:
>> Updating the last enum for rte_bbdev_op_type
>> to allow for enum insertion.
>
> Please explain that the reason is to keep ABI compatible,
> and you want to keep the MAX value for array needs.
>
>> --- a/lib/bbdev/rte_bbdev.c
>> +++ b/lib/bbdev/rte_bbdev.c
>> @@ -1122,7 +1122,10 @@ struct rte_mempool *
>>  		"RTE_BBDEV_OP_TURBO_DEC",
>>  		"RTE_BBDEV_OP_TURBO_ENC",
>>  		"RTE_BBDEV_OP_LDPC_DEC",
>> -		"RTE_BBDEV_OP_LDPC_ENC",
>> +		"RTE_BBDEV_OP_RESERVED_1",
>> +		"RTE_BBDEV_OP_RESERVED_2",
>> +		"RTE_BBDEV_OP_RESERVED_3",
>> +		"RTE_BBDEV_OP_RESERVED_4",
>
> As Stephen said, you should make sure that using these values
> with the API functions will lead to a clear and expected error.
>
>> @@ -748,7 +748,7 @@ enum rte_bbdev_op_type {
>>  	RTE_BBDEV_OP_TURBO_ENC,  /**< Turbo encode */
>>  	RTE_BBDEV_OP_LDPC_DEC,  /**< LDPC decode */
>>  	RTE_BBDEV_OP_LDPC_ENC,  /**< LDPC encode */
>> -	RTE_BBDEV_OP_TYPE_COUNT,  /**< Count of different op types */
>> +	RTE_BBDEV_OP_TYPE_COUNT = 8,  /**< Count of different op types */
>
> You must update the comment to explain there may be a padding,
> it is not exactly the count.
> Maybe "MAX" is a better fit than "COUNT" in this case.


-- 
Regards, Ray K