Patch-ID# 100364-01
Keywords: xy451, panics, driver, regs, sun4, xy450
Synopsis: SUnOS 4.1.1:  xy driver panics: regs accessed while busy
Date: 28-Aug-91
 
SunOS release: 4.1.1
 
Topic: kernel/driver  
 
BugId's fixed with this patch: 1029802 

Architectures for which this patch is available: sun4

Patches which may conflict with this patch: 

Obsoleted by: 4.1.2

Problem Description:

This panic occurs on high-speed Sun-4 CPU's - the controller cannot
set flag bits in the CSR (and let them settle) before the CPU begins
polling to see if the bits are set.  This leads to a race condition
which causes the panic: the status bits are not in the correct state
and the CPU will abort just before starting the next data transfer.
 

INSTALL:

cp /sys/sun4/OBJ/xy.o /sys/sun4/OBJ/xy.o.FCS
cp sun4/xy.o /sys/sun4/OBJ/xy.o

Regen the kernel and reboot with the new kernel.

     Please Refer to the System and Networking Administration Manual
             section on building and installing a custom kernel.


