Subject: MSCP floppy diskette driver panic (#0002)
Index:	sys/dev/mscp/mscp_disk.c NetBSD 1.6.1

$Id: 0002.txt,v 1.2 2006/06/10 14:18:52 kirk Exp kirk $

Description:
	Please note that diffs are not public domain; they are subject to
	the copyright notices on the relevant files.

	The kernel panics when you try to use a the MSCP floppy diskette
	driver.

Repeat-By:
	Setup the simh VAX emulator to boot NetBSD 1.6.1 with an
	emulated MSCP floppy diskette and hard disk.  Try to use
	the floppy diskette device:
	    simhvax# cksum /dev/rx0a
	    ra0: dk_busy < 0
	    panic: disk_unbusy
	    Stopped at      disk_unbusy+0x37:       mfpr    $18, r2

References:
	http://simh.trailing-edge.com/
	http://www.netbsd.org/cgi-bin/query-pr-single.pl?number=26138
	http://mail-index.netbsd.org/netbsd-bugs/2004/07/02/0000.html
	http://mail-index.netbsd.org/port-vax/2005/01/03/0000.html
	http://mail-index.netbsd.org/port-vax/2005/01/03/0001.html
	http://mail-index.netbsd.org/port-vax/2005/01/03/0002.html
	http://mail-index.netbsd.org/port-vax/2005/01/03/0003.html
	http://mail-index.netbsd.org/port-vax/2005/01/04/0000.html

Unit-Test:
	Used RX50 floppy drives on a microvax and simh.

Fix:
	modified: /usr/src/sys/dev/mscp/mscp_disk.c

	It appears that rriodone() is shared by the ra and rx devices.
	But rriodone() only calls disk_unbusy() with the ra context
	but never the rx context.  But the rrfillin() routine has
	has code to distinguish between the ra and rx devices.  When
	the rriodone() is modified to chech the rx/ra contect, the
	kernel doesn't panic.

	To apply this update:
		- cut where indicated and save to a file (tmp/0002)
		- run "patch  -p0 < /tmp/0002"
		- recompile and install your kernel

	This and previous updates to NetBSD 1.6.1 are available via
	http://www.ba23.org/vax911/

------------------------cut here---------------------
*** /usr/src/sys/dev/mscp/mscp_disk.c.old	Fri May 26 17:18:38 2006
--- /usr/src/sys/dev/mscp/mscp_disk.c	Fri May 26 17:19:41 2006
***************
*** 856,862 ****
  	/* We assume that this is a reasonable drive. ra_strategy should
  	   already have verified it. Thus, no checks here... /bqt */
  	unit = DISKUNIT(bp->b_dev);
! 	ra = ra_cd.cd_devs[unit];
  	disk_unbusy(&ra->ra_disk, bp->b_bcount);
  
  	biodone(bp);
--- 856,871 ----
  	/* We assume that this is a reasonable drive. ra_strategy should
  	   already have verified it. Thus, no checks here... /bqt */
  	unit = DISKUNIT(bp->b_dev);
! #if NRA
! 	if (major(bp->b_dev) == RAMAJOR) {
! 		ra = ra_cd.cd_devs[unit];
! 	}
! #endif
! #if NRX
! 	if (major(bp->b_dev) != RAMAJOR) {
! 		ra = rx_cd.cd_devs[unit];
! 	}
! #endif
  	disk_unbusy(&ra->ra_disk, bp->b_bcount);
  
  	biodone(bp);
*** /usr/src/VERSION.old	Sun May 21 09:57:05 2006
--- /usr/src/VERSION	Sun May 21 10:40:16 2006
***************
*** 1,2 ****
! Current Patch Level: 0001
  Date: May 21, 2006
--- 1,2 ----
! Current Patch Level: 0002
  Date: May 21, 2006