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

["Zhao1, Wei" <wei.zhao1@intel.com>]

> -----Original Message-----
> From: Ye, Xiaolong <xiaolong.ye@intel.com>
> Sent: Tuesday, May 19, 2020 7:39 AM
> To: Zhao1, Wei <wei.zhao1@intel.com>
> Cc: Sun, GuinanX <guinanx.sun@intel.com>; dev@dpdk.org; stable@dpdk.org;
> Min, JiaqiX <jiaqix.min@intel.com>; Yigit, Ferruh <ferruh.yigit@intel.com>
> Subject: Re: [dpdk-dev] [dpdk-stable] [PATCH v2 2/2] net/e1000: fix defects of
> macro in VF
> 
> 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.

Yes, you are right.

> 
> 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
> >> >