A Bus Timeout Error (TO event) on the System Bus means that the CPU
tried to read or write from a memory location and the device at that location did not 
respond.                        

Example:

WARNING: [AFT1] Timeout on System Bus in privileged mode from CPU0 Data access at TL=0, errID 0x0019487b.66825e5e 
AFSR 0x00000000.88000000<PRIV,TO> AFAR 0x000001ff.10700000                        

To solve this you need to identify what device on the bus caused the 
timeout. The AFAR is the address register and it contains the address 
of the faulty device.

Look for the address range in the prtconf -pv output that matches the AFAR (0x000001ff.10700000.
                        

Node 0xf005b314
        scsi-initiator-id:  00000007
        version#:  00000001
        implementation#:  00000000
        address:  fffc8000
        interrupts:  000007f4.000007f5.000007f6.000007e5.000007ea.000007f7
        ranges:
00000000.00000000.000001ff.00000000.10000000.00000001.00000000.000001ff.10000000.10000000.00000002.00000000.000001ff.20000000.10000000.00000003.00000000.000001ff.30000000.10000000.0000000d.00000000.000001ff.d0000000.10000000.0000000e.00000000.000001ff.e0000000.10000000.0000000f.00000000.000001ff.f0000000.10000000
        reg:  000001fe.00000000.00000000.00008000
        slot-address-bits:  0000001c
        up-burst-sizes:  0078007f
        burst-sizes:  00f8007f
        device_type:  'sbus'
        name:  'sbus'
        model:  'SUNW,sysio'
        thermal-interrupt:  
        bus-parity-generated:  
        upa-portid:  0000001f
        clock-frequency:  017d7840                        

The faulty part is on the device_type 'sbus'. It confirms the panic string.
Looking for each device depending on the node 0xf005b314 doesn't provide much more 
information.

We have to determine which sbus slot the timeout comes from.
You need to decode the ranges field:                       

	ranges:
00000000.00000000.000001ff.00000000.10000000.00000001.00000000.000001ff.10000000.10000000.00000002.00000000.000001ff.20000000.10000000.00000003.00000000.000001ff.30000000.10000000.0000000d.00000000.000001ff.d0000000.10000000.0000000e.00000000.000001ff.e0000000.10000000.0000000f.00000000.000001ff.f0000000.10000000

        ranges:  
00000000.00000000.000001ff.00000000.10000000.
00000001.00000000.000001ff.10000000.10000000.
00000002.00000000.000001ff.20000000.10000000.
00000003.00000000.000001ff.30000000.10000000.
0000000d.00000000.000001ff.d0000000.10000000.
0000000e.00000000.000001ff.e0000000.10000000.
0000000f.00000000.000001ff.f0000000.10000000

SLOT                 RANGE               LENGHT
slot 0          000001ff.00000000       10000000 >>>> sbus slot 0
Slot 1          000001ff.10000000       10000000 >>>> sbus slot 1
Slot 2          000001ff.20000000       10000000 >>>> sbus slot 2
Slot 3          000001ff.30000000       10000000 >>>> sbus slot 3 
Slot 13 (0xd)   000001ff.d0000000       10000000 >>>> APC & CS4231 (Line in/out, microphone)
Slot 14 (0xe)   000001ff.e0000000       10000000 >>>> FEPS (SCSI, Ethernet, // port)
Slot 15 (0xf)   000001ff.f0000000       10000000 >>>> SLAVIO (serial ports, floppy, keyboard, mouse)

WARNING
The assignment is implementation specific. 
On electron (Ultra 1 170E) and pulsar (Ultra 2), the ordering is as follows: 
slot 13 is audio (APC), slot 14 is Happy Meal, and slot 15 is Slavio. 
On neutron (Ultra 1 140/170), the ordering is as follows: 
slot 13 is audio (APC), slot 14 is Macio, and slot 15 is Slavio.

Our AFAR (0x000001ff.10700000) is included in the range of slot 1.

======================== IO Cards =========================

     Bus   Freq
Brd  Type  MHz   Slot  Name                              Model
---  ----  ----  ----  --------------------------------  ----------------------
 0   SBus   25     0   SUNW,hme                          SUNW,501-2919         
 0   SBus   25     1   gw                                DW3300                
 0   SBus   25     2   fcaw                              FCW                   
 0   SBus   25    14   SUNW,fas/sd (block)                                     
 0   SBus   25    14   SUNW,hme                                                
 0   SBus   25    14   SUNW,bpp                                                
 0   UPA   100    30   FFB, Double Buffered              SUNW,501-3129    
  
From the prtdiag output, we see that a gw card is in Slot 1 and the 
prtconf output provides more information about this 3rd party card.

Node 0xf00818bc
            ...
            copyright:  'Copyright (c) 1994 Data/Ware Development Inc.'
            manufacturer:  'Data/Ware'
            device_type:  'network'
            model:  'DW3300'
            name:  'gw'                        

In this example, the culprit is either the gw card or the system board, 
which should be replaced.                        

• Pulsar Product Specification P/N 950-2738
• SYSIO Chip Specification P/N 950-2118