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

[Thierry Herbelot <thierry.herbelot@6wind.com>]

On 9/30/19 12:58 PM, Ye Xiaolong wrote:
> Hi, Thierry & Fengtian
> 
> Any update about this patch according to Qi's comment?

Hello, Xiaolong

I agreee with Qi's comment: this patch solves one issue, but causes 
another problem.

I am completely open to any suggestion about how to retrieve the PF 
status from the VF device.

	Regards

	Thierry

> 
> Thanks,
> Xiaolong
> 
> On 09/17, Zhang, Qi Z wrote:
>>
>>
>>> -----Original Message-----
>>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Thierry Herbelot
>>> Sent: Thursday, September 12, 2019 12:01 AM
>>> To: dev@dpdk.org
>>> Cc: Guo Fengtian <fengtian.guo@6wind.com>; Thomas Monjalon
>>> <thomas@monjalon.net>; stable@dpdk.org; Lu, Wenzhuo
>>> <wenzhuo.lu@intel.com>; Ananyev, Konstantin
>>> <konstantin.ananyev@intel.com>
>>> Subject: [dpdk-dev] [PATCH 1/1] net/ixgbevf: fix stats update after a PF reset
>>>
>>> From: Guo Fengtian <fengtian.guo@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@dpdk.org
>>> Cc: wenzhuo.lu@intel.com
>>> Cc: konstantin.ananyev@intel.com
>>>
>>> Signed-off-by: Guo Fengtian <fengtian.guo@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
>>


-- 
Thierry Herbelot
6WIND
Senior Software Engineer

Tel: +33 1 39 30 92 61
Fax: +33 1 39 30 92 11
thierry.herbelot@6wind.com
www.6wind.com
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