Re: [dpdk-stable] [PATCH 0/8] Correct XXX_TX_OFFLOAD_NOTSUP_MASK

[Ye Xiaolong <xiaolong.ye@intel.com>]

Hi, Ferruh

On 11/02, Ferruh Yigit wrote:
>On 10/27/2018 11:40 AM, Xiaolong Ye wrote:
>> Hi,
>> 
>> This patch series is to correct the wrong setting of
>> XXX_TX_OFFLOAD_MASK in multiple PMDs.
>> 
>> Just as the name XXX_TX_OFFLOAD_NOTSUP_MASK indicates, it should be the
>> mask of unsupported features (either not in PKT_TX_OFFLOAD_MASK or in
>> XXX_TX_OFFLOAD_MASK), however, xor will not get desired result here,
>> assume bit 0 of PKT_TX_OFFLOAD_MASK and XXX_TX_OFFLOAD_MAKS are 0 which
>> means corresponding feature is not supported in both sides, then we get
>> value of bit 0 of XXX_TX_OFFLOAD_NOTSUP_MASK which is 0 via xor, it
>> implies that it is supported which doesn't meet our expectation.
>
>Hi Xiaolong,
>
>I am not sure if this is a problem.
>
>PKT_TX_OFFLOAD_MASK should be all TX bits set, from bit 40 to 60 in latest code.
>And XXX_TX_OFFLOAD_MASK can be subset of those bits set.
>
>So your sample doesn't apply here since PKT_TX_OFFLOAD_MASK, TX related bits,
>can't be 0. And (A ^ B) should be same with ~(A & B) for this case.
>

If this is the case, I think current code is fine. ~(A & B) is just more correct
than (A ^ B) from the logic perspective.

>
>Am I missing something, do you have a failing usecase/testcase with real values?

No real failing issue has been found, I just happened to read the code and
thought it might be a problem. :)

Thanks,
Xiaolong
>
>> 
>> Correct it by a NOT-AND operation.
>> 
>> Xiaolong Ye (8):
>>   net/ixgbe: correct offload not supported mask
>>   net/avf: correct offload not supported mask
>>   net/ena: correct offload not supported mask
>>   net/atlantic: correct offload not supported mask
>>   net/fm10k: correct offload not supported mask
>>   net/qede: correct offload not supported mask
>>   net/vmxnet3: correct offload not supported mask
>>   net/e1000: correct offload not supported mask
>> 
>>  drivers/net/atlantic/atl_rxtx.c    | 2 +-
>>  drivers/net/avf/avf_rxtx.h         | 2 +-
>>  drivers/net/e1000/em_rxtx.c        | 2 +-
>>  drivers/net/e1000/igb_rxtx.c       | 2 +-
>>  drivers/net/ena/ena_ethdev.c       | 2 +-
>>  drivers/net/fm10k/fm10k_rxtx.c     | 2 +-
>>  drivers/net/ixgbe/ixgbe_rxtx.c     | 2 +-
>>  drivers/net/qede/qede_rxtx.h       | 2 +-
>>  drivers/net/vmxnet3/vmxnet3_rxtx.c | 2 +-
>>  9 files changed, 9 insertions(+), 9 deletions(-)
>> 
>