Re: [dpdk-stable] [dpdk-dev] [PATCH v2 2/2] net/e1000: fix defects of macro in VF

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

Hi, wei

On 05/18, Zhao1, Wei wrote:
>Hi, xiaolong
>
>> -----Original Message-----
>> From: dev <dev-bounces@dpdk.org> On Behalf Of Ye Xiaolong
>> Sent: Monday, May 18, 2020 9:25 AM
>> To: Sun, GuinanX <guinanx.sun@intel.com>
>> Cc: dev@dpdk.org; stable@dpdk.org
>> Subject: Re: [dpdk-dev] [dpdk-stable] [PATCH v2 2/2] net/e1000: fix defects of
>> macro in VF
>>
>> Hi, guinan
>>
>> On 05/08, Guinan Sun wrote:
>> >The defects in the macros UPDATE_VF_STAT and UPDATE_VF_STAT_36BIT
>> exist.
>> >If latest is less than last, we will get wrong result.
>> >The patch fixes the defect.
>>
>> There was similar patch before, https://patches.dpdk.org/patch/65131/, if I
>> understand it correctly, you are trying to solve the rollover issue, right?
>> Could you find the Ferruh's comment and check if this is a real issue?
>
>this issue has not been fixed by now, we need this patch to fix it.
>If (latest < last), there will be issue, is that right?

Actually the rollover case has been covered by original code.

Thanks,
Xiaolong


>
>
>>
>> >
>> >Fixes: d15fcf76c8b7 ("e1000: move to drivers/net/")
>>
>> This fix commit isn't correct.
>>
>> Thanks,
>> Xiaolong
>>
>> >Cc: stable@dpdk.org
>>
>>
>>
>> >
>> >Signed-off-by: Guinan Sun <guinanx.sun@intel.com>
>> >---
>> >v2 changes:
>> >* Aligned line-continuation character "\".
>> >---
>> > drivers/net/e1000/igb_ethdev.c | 18 +++++++++++++-----
>> > 1 file changed, 13 insertions(+), 5 deletions(-)
>> >
>> >diff --git a/drivers/net/e1000/igb_ethdev.c
>> >b/drivers/net/e1000/igb_ethdev.c index 520fba8fa..4cd4e55c0 100644
>> >--- a/drivers/net/e1000/igb_ethdev.c
>> >+++ b/drivers/net/e1000/igb_ethdev.c
>> >@@ -47,6 +47,8 @@
>> > #define IGB_4_BIT_MASK   RTE_LEN2MASK(IGB_4_BIT_WIDTH, uint8_t)
>> > #define IGB_8_BIT_WIDTH  CHAR_BIT
>> > #define IGB_8_BIT_MASK   UINT8_MAX
>> >+#define IGB_32_BIT_WIDTH (CHAR_BIT * 4) #define IGB_32_BIT_MASK
>> >+RTE_LEN2MASK(IGB_32_BIT_WIDTH, uint32_t)
>> >
>> > /* Additional timesync values. */
>> > #define E1000_CYCLECOUNTER_MASK      0xffffffffffffffffULL
>> >@@ -261,11 +263,17 @@ static int igb_filter_restore(struct rte_eth_dev
>> >*dev);
>> > /*
>> >  * Define VF Stats MACRO for Non "cleared on read" register
>> >  */
>> >-#define UPDATE_VF_STAT(reg, last, cur)            \
>> >-{                                                 \
>> >-u32 latest = E1000_READ_REG(hw, reg);     \
>> >-cur += (latest - last) & UINT_MAX;        \
>> >-last = latest;                            \
>> >+#define UPDATE_VF_STAT(reg, last, cur)
>> \
>> >+{
>>      \
>> >+uint64_t latest = E1000_READ_REG(hw, reg);                 \
>> >+uint64_t stat = 0;                                         \
>> >+if (latest >= last)                                        \
>> >+stat = latest - last;                              \
>> >+else                                                       \
>> >+stat = (uint64_t)((latest +                        \
>> >+((uint64_t)1 << IGB_32_BIT_WIDTH)) - last);\
>> >+cur += stat & IGB_32_BIT_MASK;                             \
>> >+last = latest;                                             \
>> > }
>> >
>> > #define IGB_FC_PAUSE_TIME 0x0680
>> >--
>> >2.17.1
>> >