From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Mon,  5 Oct 1998 04:17:26 -0400
From: arisawa@ar.aichi-u.ac.jp arisawa@ar.aichi-u.ac.jp
Subject: [9fans] 9fs and 1542
Topicbox-Message-UUID: 833a3be0-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19981005081726.hwXLxZ-UJlZUZrVbHQaoO5Lq0AmQfhvwZ0I8p3mgAXA@z>

Hello 9fans!

I wrote on the 1542 problem on file server :
># This time I attached only one scsi disk ( scsiid=0 ). #
>I found that the problem comes from scsiprobe() in `fs/pc/scsi.c'.
>I inserted print statements in scsiprobe():

I did some experiments:
case 1
	One HD on id=0
	result:
		scsiprobe can recognize:
			the presence of id=0
			the absence of id=1
		and freezes at id=2
case 2
	Two HDs on id=0 and 1
	result:
		scsiprobe can recognize:
			the presence of id=0
			the presence of id=1
			the absence of id=2
		and freezes at id=3
case 3
	Two HDs on id=0 and 2
	result:
		scsiprobe can recognize:
			the presence of id=0
			the absence of id=1
			the presence of id=2
		and freezes at id=3
case 4
	Three HDs on id=0, 2 and 3
	result:
		scsiprobe can recognize:
			the presence of id=0
			the absence of id=1
			the presence of id=2
			the presence of id=3
		and freezes at id=4
		
I investigated freezing point. The result is shown bellow:
	scsiprobe in fs/pc/scsi.c
	aha1542io in fs/pc/scsi1542.c
	sleep in fs/port/proc.c
	sched in fs/port/proc.c

Any advice is welcome.

Kenji Arisawa
E-mail: arisawa@aichi-u.ac.jp