[1480] in linux-scsi channel archive
Strange SCSI bus reset caused by HP C4324 CD-R. Why?
daemon@ATHENA.MIT.EDU (Jeffrey Wiegley)
Fri Feb 28 04:08:57 1997
Date: Fri, 28 Feb 1997 01:05:52 -0800
From: Jeffrey Wiegley <wiegley@usc.edu>
To: linux-scsi@vger.rutgers.edu
I recently installed a Hewlett Packard CD-recorder (model C4324). It
works great except for one thing that I think is strange (and annoying).
When I try to mount the CD-ROM before it has spun up completely the
entire SCSI bus gets reset and my system freezes for about 10 seconds.
This is rather annoying behavior since all the other CD-ROM drives
(non-recordable) have always just returned a sort of "drive not ready"
error to mount but at least they wouldn't make the machine unusable for
10 seconds.
here's more information than you probably care to know about but I was
hoping that somebody knew what was going on, whether it was correct
behavior or whether it could be fixed/improved...
here's so you know what I have attached to the SCSI BUS:
[wiegley@enigma wiegley]$ cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: SEAGATE Model: ST15150W Rev: 0023
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: HP Model: C4324/C4325 Rev: 1.27
Type: CD-ROM ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 02 Lun: 00
Vendor: WANGTEK Model: 6130-HS Rev: 4G16
Type: Sequential-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 03 Lun: 00
Vendor: HP Model: C2520A Rev: 3503
Type: Processor ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 04 Lun: 00
Vendor: SEAGATE Model: ST15150W Rev: 0023
Type: Direct-Access ANSI SCSI revision: 02
Here's so you know how my Adaptec 2940 is doing:
[wiegley@enigma wiegley]$ cat /proc/scsi/aic7xxx/0
Adaptec AIC7xxx driver version: 4.0/3.2/4.0
Compile Options:
AIC7XXX_RESET_DELAY : 15
AIC7XXX_CMDS_PER_LUN : 16
AIC7XXX_TWIN_SUPPORT : Enabled
AIC7XXX_TAGGED_QUEUEING: Enabled
AIC7XXX_PAGE_ENABLE : Enabled
AIC7XXX_PROC_STATS : Disabled
Adapter Configuration:
SCSI Adapter: AIC-7870
(AIC-787x chipset)
Host Bus: Wide
Base IO: 0x6100
IRQ: 11
SCBs: Used 17, HW 16, Page 255
Interrupts: 20264
Serial EEPROM: True
Extended Translation: Disabled
SCSI Bus Reset: Enabled
Ultra SCSI: Disabled
Target Disconnect: Enabled
now here's what happens when I try to mount the volume with the drive
tray completely open:
[wiegley@enigma wiegley]$ mount /mnt/cdrom
mount: /dev/scd0 is not a valid block device
This is what happens when I try to mount the volume just after closing
the try:
[wiegley@enigma wiegley]$ mount /mnt/cdrom
[wiegley@enigma wiegley]$
Except what you don't see is that the whole machine froze for ten
seconds between the command and the next prompt. So this is what I get
in /var/log/messages:
Feb 28 01:04:34 enigma kernel: Disc change detected.
Feb 28 01:04:34 enigma kernel: scsi0: Target busy, TCL=0x10.
Feb 28 01:04:35 enigma kernel: scsi0: Target busy, TCL=0x10.
Feb 28 01:04:35 enigma kernel: scsi0 channel 0 : resetting for second
half of retries.
Feb 28 01:04:35 enigma kernel: SCSI bus is being reset for host 0
channel 0.
Feb 28 01:04:35 enigma kernel: aic7xxx: (reset) target/channel 1/0
Feb 28 01:04:35 enigma kernel: aic7xxx: (reset_device) target/channel
-1/A, active_scb 9
Feb 28 01:04:35 enigma kernel: aic7xxx: (match_scb) comparing
target/channel -1/A to scb 0/A
Feb 28 01:04:35 enigma kernel: aic7xxx: (match_scb) comparing
target/channel -1/A to scb 0/A
Feb 28 01:04:35 enigma kernel: aic7xxx: (reset_channel) Resetting
current channel A
Feb 28 01:04:35 enigma kernel: aic7xxx: (reset_channel) Channel reset,
sequencer restarted
Feb 28 01:04:35 enigma kernel: aic7xxx: (done_aborted_scbs) Aborting
scb 14, TCL=0/0/0
Feb 28 01:04:35 enigma kernel: aic7xxx: (done_aborted_scbs) Aborting
scb 15, TCL=0/0/0
Feb 28 01:04:35 enigma kernel: scsi0: Received MSG_WDTR, Target 0,
channel A needwdtr(0xfff1).
Feb 28 01:04:35 enigma kernel: scsi0: Target 0, channel A, using 16
bit transfers.
Feb 28 01:04:35 enigma kernel: scsi0: Target 0, channel A, now
synchronous at 10.0MHz, offset 8.
Feb 28 01:04:35 enigma kernel: scsi0: Target 1, channel A, refusing
synchronous negotiation; using asynchronous transfers.
Feb 28 01:04:41 enigma kernel: CDROM (ioctl) reports ILLEGAL REQUEST.
Whats up here?
- Jeff
