misc/172968: [arswitch] probe/attach occasionally fails to find a PHY

[Adrian Chadd]

>Number:         172968
>Category:       misc
>Synopsis:       [arswitch] probe/attach occasionally fails to find a PHY
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Oct 22 22:30:01 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Adrian Chadd
>Release:        -HEAD, mips
>Organization:
>Environment:
>Description:
Occasionally the probe/attach of the AR8316 switch fails - the actual device doesn't fail, but the mdiobus it exposes doesn't always find a PHY.

This means that sometimes one of the on-board arge interfaces (which is linked to the stand-alone PHY) can't find a PHY and it simply fails to attach.
>How-To-Repeat:
Just keep rebooting an atheros MIPS board with an onboard AR8x16 switch.
>Fix:
Luis Otavio D'Souza found that disabling the page cache feature fixes it.
Ie, always set the page id before read/writing the switch register.


>Release-Note:
>Audit-Trail:
>Unformatted: