Description

This document explains regarding error "RE0 IIC access Error" and how to clear the same.

 

Symptoms

We can see RE0 IIC access error minor alarm on the chassis.

root@LAB_RE0> show chassis alarms 
1 alarms currently active
Alarm time               Class  Description
2023-08-02 02:31:38 EDT  Minor  RE0 IIC access Error

We can see this alarm when there are active errors on routing engine.
 
root@LAB_RE0> show chassis routing-engine errors
Aug 03 00:14:45
Module_id      Name          DeviceId    Threshold     ActiveErr   Occured   Cleared  DeviceDesc
      0       REFPGA         006A0000    1              0           0         0          REFPGA  
      1       VT1527         00600000    1              3           3         0          VT1527  
      2      IDEEPROM        00530000    1              0           0         0          IDEEPROM
      3      TMP75EXHAUST    00480000    1              1578        1578      0          TMP75_EXHAUST_48
      4      TMP75INTAKE     004E0000    1              5           5         0          TMP75_INTAKE_4E
      5      I2CLTC3880      00430000    1              21          21        0          I2CLTC3880
      6      I2CADS7830      004B0000    1              9           9         0          I2CADS7830
      7      ADSSensor       FF4B0405    1              0           0         0          ads7830_.85V_rail
                             FF4B2905    1              0           0         0          ads7830_1.1V_rail
                             FF4B2D05    1              0           0         0          ads7830_1.2V_rail
                             FF4B4805    1              0           0         0          ads7830_1.5V_rail
                             FF4B5C05    1              0           0         0          ads7830_2.5V_rail
                             FF4B6205    1              0           0         0          ads7830_3.3V_rail
                             FF4B7B05    1              0           0         0          ads7830_5V_rail
                             FF4B8C05    1              0           0         0          ads7830_12V_rail
      8      VT1527Sensor    FF60070B    1              0           0         0          vt1527_0.9V_rail
      9      LTCSensor       FF432E07    1              0           0         0          ltc3880_1.2V_2rail
                             FF432807    1              0           0         0          ltc3880_1.2V_rail
     10      00520000UMON    99990001    1              0           0         0          unmonitord
 

Collision error is detected for ichsmb process on RE0 and these logs are continuously seen on RE0:

Aug  2 23:52:58 2023  LAB_RE0 kernel: ichsmb_device_intr: Collision Error ICH_HST_STA: 0x8
Aug  2 23:52:58 2023  LAB_RE0 kernel: collision found: retry_count:1

Check if the interrupts are incrementing using below command:

root@LAB_RE0> show system virtual-memory | find "interrupt                          total       rate" 
interrupt                          total       rate
irq4: uart0                         1656          0
irq14: ata0                       455650          1
irq15: ata1                            1          0
irq18: ichsmb0                   1265874          2
irq23: ehci0                     1582095          2
cpu0:timer                     135078024        171
irq256: em0                     78496193         99
irq257: em1                      1581938          2
irq258: em2                       968650          1
cpu3:timer                      62057933         78
cpu1:timer                      60824132         77
cpu2:timer                      61433959         78
Total                          403746105        510
vm.kmem_map_free: 33306480640

 

Solution

The alarm will be cleared automatically within 24 hours. The clear time is based on the time when chassisd starts working on master RE and crafted and alarmed are connected to chassisd. 

We also need to check the statistics from "show chassis routing-engine errors". If there are a lot of erros on a certain of module, please create a JTAC case for further investigation. 

 

Modification History

First Draft: 07/08/2023

08-Nov-24 Corrected improvement PR info