[dpdk-stable] [dpdk-dev] [PATCH 1/1] net/ixgbevf: fix stats update after a PF reset

[Zhang, Qi Z]

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Thierry Herbelot
> Sent: Thursday, September 12, 2019 12:01 AM
> To: dev at dpdk.org
> Cc: Guo Fengtian <fengtian.guo at 6wind.com>; Thomas Monjalon
> <thomas at monjalon.net>; stable at dpdk.org; Lu, Wenzhuo
> <wenzhuo.lu at intel.com>; Ananyev, Konstantin
> <konstantin.ananyev at intel.com>
> Subject: [dpdk-dev] [PATCH 1/1] net/ixgbevf: fix stats update after a PF reset
> 
> From: Guo Fengtian <fengtian.guo at 6wind.com>
> 
> When PF is set down, in VF, the value of stats register is zero.
> So only increase stats when it's non zero.
> 
> Fixes: af75078fece3 ('first public release')
> Cc: stable at dpdk.org
> Cc: wenzhuo.lu at intel.com
> Cc: konstantin.ananyev at intel.com
> 
> Signed-off-by: Guo Fengtian <fengtian.guo at 6wind.com>
> ---
>  drivers/net/ixgbe/ixgbe_ethdev.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
> b/drivers/net/ixgbe/ixgbe_ethdev.c
> index 7eb3d0567b58..27c540f60563 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> @@ -385,7 +385,8 @@ static void ixgbe_l2_tunnel_conf(struct rte_eth_dev
> *dev);
>  #define UPDATE_VF_STAT(reg, last, cur)                          \
>  {                                                               \
>  	uint32_t latest = IXGBE_READ_REG(hw, reg);              \
> -	cur += (latest - last) & UINT_MAX;                      \
> +	if (latest)                                             \
> +		cur += (latest - last) & UINT_MAX;              \

There is still a chance that PF is up but the latest reg read returns 0, since it's a cyclic counter, is any way to check the PF status directly?

>  	last = latest;                                          \
>  }
> 
> @@ -394,7 +395,8 @@ static void ixgbe_l2_tunnel_conf(struct rte_eth_dev
> *dev);
>  	u64 new_lsb = IXGBE_READ_REG(hw, lsb);                   \
>  	u64 new_msb = IXGBE_READ_REG(hw, msb);                   \
>  	u64 latest = ((new_msb << 32) | new_lsb);                \
> -	cur += (0x1000000000LL + latest - last) & 0xFFFFFFFFFLL; \
> +	if (latest)                                              \
> +		cur += (0x1000000000LL + latest - last) & 0xFFFFFFFFFLL;\
>  	last = latest;                                           \
>  }
> 
> --
> 2.20.1