[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
Re: kern/37403: USB tape drive Illegal Requests for any use
The following reply was made to PR kern/37403; it has been noted by GNATS.
From: Jesse Peterson <jpeterson275%comcast.net@localhost>
Cc: Manuel Bouyer <bouyer%antioche.eu.org@localhost>,
Subject: Re: kern/37403: USB tape drive Illegal Requests for any use
Date: Mon, 19 Oct 2009 09:25:22 -0700
After finally getting a chance to pick this up again I've found an (ugly)
solution to this issue.
The problem in the logs here seem to indicate a SCSI error when attempting to
MODE SELECT. After some investigation into the details of that it eventually
came to be that the block size was getting set to 0 and thus reported as such
to the MODE SELECT SCSI command. I'm not sure if this is because the value is
not between the allowed block size (2 <= blksize <= 16777215) or because the
blksize is not changanble (the change mask a la PC field is not queried in the
MODE SENSE) or what. What I do know is that the tape drive seems to start
working great when this patch is applied:
--- sys/dev/scsipi/st.c.orig 2008-11-19 18:50:27.000000000 -0800
+++ sys/dev/scsipi/st.c 2009-10-19 08:48:50.000000000 -0700
@@ -1024,10 +1024,24 @@
* We're getting no hints from any direction. Choose variable-
* length blocks arbitrarily.
st->flags &= ~ST_FIXEDBLOCKS;
st->blksize = 0;
("Give up and default to variable mode\n"));
+ /* force block size */
+ if (st->media_blksize > 0)
+ st->flags |= ST_FIXEDBLOCKS;
+ st->flags &= ~ST_FIXEDBLOCKS;
+ st->blksize = st->media_blksize;
+ SC_DEBUG(st->sc_periph, SCSIPI_DB3,
+ ("Give up and default to media_blksize of %d\n",
+ goto done;
Which successfully does the MODE SELECT with the right block size (512 in this
Now obviously this isn't good for all devices (as implemented in this patch) -
just note that it works for this hardware. I'm not sure if this particular
drive cannot do variable-sized blocks (in which case a drive quirk would work
okay I think) or this is an artifact of the In-System ISD-300 ATAPI-to-USB SCSI
over Bulk-Only adapter chip that this is using. I think it is the former
because the same exact issue come ups when I use the drive over FireWire which
uses an Oxford 911 IEEE1394 adapter chip (which also does SCSI over SBP-2).
I think the right solution is to do a drive quirk only if the drive is not
directly SCSI attached? While I couldn't find any definitive docs this is a
somewhat modern drive (AIT-1) which makes me think variable blocks (0 size)
shouldn't be a problem.
P.S. As an aside why do ATAPI drives not do an actual MODE SELECT command? The
function returns an error when it is attempted for ATAPI tape drive.
Main Index |
Thread Index |