[QFX] Parity error detection and correction

Summary:

On QFX5100/QFX3500 platforms which are running running Junos 12.3X50 which used SDK version 5.9.x only parity error detection is supported but correction mechanism is not supported. You may encounter the parity which does not get cleared on its own resulting in traffic loss or other unwanted problems.

Symptoms:

On QFX platforms, you may see the following messages if it encounters a parity error:

 _soc_mem_array_sbusdma_read: L3_ENTRY_IPV4_UNICAST.ipipe0 failed(ERR)
_soc_mem_array_sbusdma_read: L2_ENTRY.ipipe0 failed(ERR)
 EGR_IP_TUNNEL.epipe0 failed(ERR)

fpc0 _soc_xgs3_mem_dma: L2_ENTRY.ipipe0 failed(NAK) _
soc_xgs3_mem_dma: L2_ENTRY.ipipe0 failed(NAK)

Cause:

Run the following command from shell to confirm if the parity has been encountered and whether it has been cleared:

start shell

cprod -A fpc0 -c 'set dcbcm bcmshell "soc"'



% cprod -A fpc0 -c 'set dcbcm bcmshell "soc"'

HW (unit 0)

  Unit 0 Driver Control Structure:

  Chip=BCM56960_B1 Rev=0x12 Driver=BCM56960_A0

  Flags=0x40107: attached initialized link-scan mem-clear-use-dma; board type 0x0

  CM: Base=0x0

  Disabled: reg_flags=0x100 mem_flags=0x0

  SchanOps=-1008392477 MMUdbg=0 LinkPause=0

  Counter: int=500000us per=1610000us dmaBuf=0xaabae030

  Timeout: Schan=0(300000us) MIIM=0(300000us)

  Intr: Total=161036084 Sc=0 ScErr=0 MMU/ARLErr=0

        LinkStat=639 PCIfatal=0 PCIparity=0

        ARLdrop=0 ARLmbuf=0 ARLxfer=0 ARLcnt0=0

        TableDMA=0 TSLAM-DMA=0 CCM-DMA=0 SW=0

        MemCmd[BSE]=0 MemCmd[CSE]=0 MemCmd[HSE]=0

        ChipFunc[0]=0 ChipFunc[1]=0 ChipFunc[2]=0

        ChipFunc[3]=0 ChipFunc[4]=0

        FifoDma[0]=0 FifoDma[1]=814428 FifoDma[2]=0 FifoDma[3]=0

        I2C=0 MII=0 StatsDMA=0 Desc=116461685 Chain=59818101

  Error: SDRAM=0 CFAP=0 Fcell=0 MmuSR=0

  SER events(mem=1 reg=0 nak=0 stat=0 ecc=0 direct=0 fifo=1 tcam=0)

  SER corrections(fix=0 clear=1 restore=0 special=0 err:0)

  PKT DMA: dcb=t32 tpkt=139164944 tbyt=2174244743 rpkt=139954767 rbyt=2888723811

  DV: List: max-q=512 cur-tq=512 cur-rq=0 dv-size=256

  DV: Statistics: allocs=51071024 frees=51070964 alloc-q=51069799

  Mem cache (count=362 size=20290304 vmap size=164672 errmap size=8552)

  Reg cache (count=28 size=3008320)

  dma-ch-0 TX Idle   Queue=0 (0x0) default intr mbm

  dma-ch-1 RX Active Queue=20 (0xbb889e58) default intr mbm

  dma-ch-2 RX Active Queue=20 (0xbb93d330) intr mbm

  dma-ch-3 RX Active Queue=20 (0xbb9f2018) intr mbm

SER event and corrections in the above output shows if the parity has occurred and whether it was cleared or not. For all the Junos versions 14.1X53 or above which uses SDK version 6.3.7, the errors get corrected by the software. However, for the versions prior to 14.1X53, correction is not supported.

Solution:

Reboot the device using the command, "request system reboot" to recover the parity error. However there will always be a chance of parity error coming back and it would need a manual reboot again to clear it.
OR
Upgrade the device to Junos 14.1X53 which uses SDK 6.3.7 and supports both parity error detection/correction mechanisms.

Knowledge Base