[Intel-wired-lan] [next PATCH S63 5/6] i40e/i40evf: Add legacy-rx private flag to allow fallback to old Rx flow

[Alexander Duyck]

On Fri, Mar 17, 2017 at 8:57 AM, Alexander Duyck
<alexander.duyck at gmail.com> wrote:
> On Tue, Mar 14, 2017 at 10:15 AM, Bimmy Pujari <bimmy.pujari at intel.com> wrote:
>> From: Alexander Duyck <alexander.h.duyck at intel.com>
>>
>> This patch adds a control which will allow us to toggle into and out of the
>> legacy Rx mode.  The legacy Rx mode is what we currently do when performing
>> Rx.  As I make further changes what should happen is that the driver will
>> fall back to the behavior for Rx as of this patch should the "legacy-rx"
>> flag be set to on.
>>
>> Signed-off-by: Alexander Duyck <alexander.h.duyck at intel.com>
>> Change-ID: I0342998849bbb31351cce05f6e182c99174e7751
>> ---
>> Testing Hints:
>>         This flag should not appear on kernels prior to 4.10.
>>         On kernels 4.10 and later the "legacy-rx" flag should appear
>>         and can be toggled between on and off. As we add more features the
>>         behavior of the driver should change when this value is toggled.
>>
>>         Toggling this for now will only cause a reset of the interface.
>>
>>         For the VF we are specifically replacing the define that was
>>         stripping the code for the flag needed for the "legacy-rx" flag
>>         since it doesn't make sense to have the interface defined when
>>         there are no flags present.  In the case of a kernel build the
>>         #ifdefs should be stripped and the code will remain.
>>
>>  drivers/net/ethernet/intel/i40e/i40e.h             |   1 +
>>  drivers/net/ethernet/intel/i40e/i40e_ethtool.c     |   5 +-
>>  drivers/net/ethernet/intel/i40evf/i40evf.h         |   2 +
>>  drivers/net/ethernet/intel/i40evf/i40evf_ethtool.c | 104 +++++++++++++++++++++
>>  4 files changed, 111 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/net/ethernet/intel/i40e/i40e.h b/drivers/net/ethernet/intel/i40e/i40e.h
>> index dcba258..561fe1f 100644
>> --- a/drivers/net/ethernet/intel/i40e/i40e.h
>> +++ b/drivers/net/ethernet/intel/i40e/i40e.h
>> @@ -430,6 +430,7 @@ struct i40e_pf {
>>  #define I40E_FLAG_TEMP_LINK_POLLING            BIT_ULL(55)
>>  #define I40E_FLAG_CLIENT_L2_CHANGE             BIT_ULL(56)
>>  #define I40E_FLAG_WOL_MC_MAGIC_PKT_WAKE                BIT_ULL(57)
>> +#define I40E_FLAG_LEGACY_RX                    BIT_ULL(57)
>
> It looks like we lost sync between upstream and out-of-tree at some
> point.  We are defining both of these using the same bit.  We need to
> use a different value for the LEGACY_RX bit in the upstream it looks
> like.

Any chance we can get a fix for this?  It has been almost a week since
I pointed out that we have a duplicate bit here, and I haven't seen
any updates.

We either need to submit a new version of this patch with us setting
I40E_FLAG_LEGACY_RX as bit 58, or if we can just get the tweak made to
the patch while it is in the tree I would be good with that as well.
We have some other patches that are going to be adding some more flags
in the pipeline and I would rather not have to push a fix for this and
instead have it fixed in the patch.

- Alex