How identify i210-AT SDP Time Stamp Event issue

[Thomas_tang]

Hi all,

 A I210-AT chip defined with SDP0, the SDP0 is a input as PPS source.  I210-AT is embedded in a CPU module. The SDP function is configured as external time function. The PPS source is normally 2 square wave per second, each wave width is 500ms. According to the i210 datasheet, when the level change SYSTIM is latched into AUXSTMPL/H. 

But in the igb driver, i found that sometimes more than twice interrupts per second. how to identify this root cause.

My observation is:

[ 3121.756892] igb_msix_other entry
[ 3121.758825] tsicr value 32
[ 3121.758830] timestamp 1593403118873225068
[ 3121.762955] sys timestamp 1593403118880067386
[ 3122.084124] igb_msix_other entry
[ 3122.086060] tsicr value 33                                                        <- this is an unexpected, more Time Stamp Event
[ 3122.086065] timestamp 1593403119200457212
[ 3122.090191] sys timestamp 1593403119207302983
[ 3122.256901] igb_msix_other entry
[ 3122.258841] tsicr value 32
[ 3122.258847] timestamp 1593403119373225940
[ 3122.262970] sys timestamp 1593403119380082562
[ 3122.756917] igb_msix_other entry
[ 3122.758856] tsicr value 32
[ 3122.758860] timestamp 1593403119873226820
[ 3122.762986] sys timestamp 1593403119880097499

igb driver info:

InceptioAGL:~# ethtool -i eth-ptp
driver: igb
version: 5.6.0-k
firmware-version: 3.25, 0x800005cc
expansion-rom-version:
bus-info: 0000:0b:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes

Any suggestion is thankful.

[CarlosAM_INTEL]

Hello, @Thomas_tang:

Thank you for contacting Intel Embedded Community.

We want to address the following questions to understand the reported issue: 

Could you please let us the procedure followed to obtain the driver related to the reported situation and where to find it?

Is this condition related to a specific version of the driver or does it happen with different versions? Please mention the tested versions and the results with each one.

We are waiting for your answer.

Best regards,

@CarlosAM_INTEL.