Re: [dpdk-stable] [PATCH] net/i40e: fix no response from kernel PF

["Wu, Jingjing" <jingjing.wu@intel.com>]

> -----Original Message-----
> From: Xing, Beilei
> Sent: Monday, July 17, 2017 3:13 PM
> To: Wu, Jingjing <jingjing.wu@intel.com>
> Cc: stable@dpdk.org
> Subject: [PATCH] net/i40e: fix no response from kernel PF

net/i40e: fix virtchnl message response timeout

> 
> If using old kernel driver and using kernel PF and DPDK VF mode, VF fails to
> start due to incomplete command.

PF driver and VF driver communicated with each other by virtual channel
message. When VF sends to message to PF to enable some offload capability,
PF should response if it is successful or not.

VIRTCHNL_OP_ENABLE_VLAN_STRIPPING is a new added message and the old
PF driver doesn't support that. So no response is received by DPDK VF. Then
VF is blocked on this message and cannot roll back.

> The root cause is that old kernel driver doesn't support vlan stripping, when
> DPDK VF sends VIRTCHNL_OP_ENABLE_VLAN_STRIPPING to kernel PF, PF won't
> response to VF.
> This patch adds clearing command on VF side if PF won't response to VF, avoids
> blocking the following commands.

This patch clears the pending command on VF side when the waiting duration
expires to avoid blocking following communication.