Description

This article will provide a explanation of PIO errors.

Dec 22 20:45:12.361 switch fpc0 trinity_pio: 20 PIO errors occurred

Dec 22 20:45:12.361 switch fpc0 trinity_pio: Last error: 10 pe4 Paradise PCI 0x00000150 Read PCIe 0

Symptoms

  1. The switch was running on code version 22.4R3-S2.11. The following errors appeared in the switch syslogs.


Dec 22 20:44:52.361 switch fpc0 trinity_pio: 16 PIO errors occurred

Dec 22 20:44:52.361 switch fpc0 trinity_pio: Last error: 10 pe4 Paradise PCI 0x00000150 Read PCIe 0

Dec 22 20:44:52.361 switch fpc0 trinity_pio: Last error: Register Addr 0x05908150

Dec 22 20:45:02.372 switch fpc0 trinity_pio: 20 PIO errors occurred

Dec 22 20:45:02.383 switch fpc0 trinity_pio: Last error: 10 pe4 Paradise PCI 0x00000150 Read PCIe 0

Dec 22 20:45:02.392 switch fpc0 trinity_pio: Last error: Register Addr 0x05908150

Dec 22 20:45:12.361 switch fpc0 trinity_pio: 20 PIO errors occurred

Dec 22 20:45:12.361 switch fpc0 trinity_pio: Last error: 10 pe4 Paradise PCI 0x00000150 Read PCIe 0

Dec 22 20:45:12.361 switch fpc0 trinity_pio: Last error: Register Addr 0x05908150

Dec 22 20:45:22.362 switch fpc0 trinity_pio: 20 PIO errors occurred

Dec 22 20:45:22.362 switch fpc0 trinity_pio: Last error: 10 pe4 Paradise PCI 0x00000150 Read PCIe 0

Dec 22 20:45:22.362 switch fpc0 trinity_pio: Last error: Register Addr 0x05908150 


  • No chassis alarms or core dumps were observed.

Solution

These errors occur when the FPC is trying to read/write some data from one of the PFE ASICs via PCI bus and it failed to do so. 

A single occurrence of this message likely indicates a one-time transient hardware error. However, multiple consecutive occurrences suggest persistent underlying issues, possibly related to a faulty FPC. In such cases, an FPC reboot resolve the issue.


As a workaround, please proceed to reboot the effected FPC in a maintenance window and monitor the logs.

user@switch> request chassis fpc slot slot-number (offline | online | restart)


For further assistance and to investigate the root cause, please open a JTAC case.


Modification History

2025-01-10 : Article Created