Patch-ID# 100309-01
Keywords: esp0, host_adapter, maxtor
Synopsis: SunOS 4.0.3c ESP0: STATUS GET FAILS : MSF=0X2
Date: 31-May-91
 
SunOS release: 4.0.3c
 
Unbundled Product: 
 
Unbundled Release: 
 
Topic: scsa/host_adapter 
 
BugId's fixed with this patch: 1059085 

Architectures for which this patch is available: sun4/40

This bug was due to a bug in the maxtor LXT200 drive which performed
some unexpected phase transitions which were not supported in the
4.0.3c esp driver but were supported in the 4.1.1 driver.
The work around for this bug was to selectively lift some code from the 
4.1.1 driver and add it to 4.0.3c driver. It is *very* unlikely that this
could break normal operation of the esp driver but it is *strongly*
recommended not to use this patch on other platforms or with any other
type of disks than the maxtor LXT200.


Patches which may conflict with this patch: 

Obsoleted by: sunos 4.1c, sunos 4.1.1c 

Problem Description: 

The root cause of the problem is that the maxtor LXT200 drive
transfers 1 byte in the data phase, then sends a save data pointer message,
and then drops of the bus.

The 4.0.3c esp driver is not so tolerant of this "unconventional"
behavior and sends a msg reject; the target rejects the reject and then
drops of the bus.

The 4.1.1 driver accepts the save data pointer message and then handles
the unexpected disconnect. The disk driver resubmits and everything
is fine.

INSTALL:

  as root:

  mv /sys/sun4c/OBJ/esp.o /sys/sun4c/OBJ/esp.o.orig
  cp sun4c/esp.o /sys/sun4c/esp.o

  Rebuild and install a new kernel and reboot the system.
  Please refer to the Systems and Networking Administration
  Manual on building and installing a custom kernel.