Date: Mon, 1 Dec 1997 00:25:23 +0100 (MET) From: wilko@yedi.iaf.nl To: FreeBSD-gnats-submit@FreeBSD.ORG Subject: kern/5181: patch to allow slow scsi cdroms more time to startup Message-ID: <199711302325.AAA28132@yedi.iaf.nl> Resent-Message-ID: <199711302340.PAA14373@hub.freebsd.org>
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>Number: 5181
>Category: kern
>Synopsis: patch to allow slow scsi cdroms more time to startup
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sun Nov 30 15:40:01 PST 1997
>Last-Modified:
>Originator: Wilko Bulte
>Organization:
Private FreeBSD site - Arnhem, The Netherlands
>Release: FreeBSD 2.2.1-RELEASE i386
>Environment:
FreeBSD 2.2.1-R but also applicable to FreeBSD-2.2.5R
Toshiba XM5701 12x SCSI cdrom connected to a NCR810
>Description:
Some SCSI cdroms are slow to react to a start_unit command after the
media has been changed. While getting up to speed, they report
'not ready'. This makes the cd_open() fail immediately with ENXIO,
resulting in misleading 'device not configured' errors when 'mount'
is run.
>How-To-Repeat:
Change media and immediately perform mount of the cdrom.
>Fix:
Below is a diff -c based on the 2.2.1R sources for /sys/scsi/cd.c
that fixes the issue:
*** cd.c.orig Wed Nov 26 20:18:54 1997
--- cd.c Mon Dec 1 00:12:05 1997
***************
*** 246,251 ****
--- 246,252 ----
errval errcode = 0;
u_int32_t unit, part;
struct scsi_data *cd;
+ int n = 0;
unit = CDUNIT(dev);
part = PARTITION(dev);
***************
*** 285,295 ****
--- 286,312 ----
scsi_start_unit(sc_link, CD_START);
SC_DEBUG(sc_link, SDEV_DB3, ("'start' attempted "));
sc_link->flags |= SDEV_OPEN; /* unit attn errors are now errors */
+
+ /* Some drives e.g. Toshiba's tend to take a long time to become ready
+ * after a disc swap and report 'Not Ready' while doing so.
+ * They should have reported 'Unit In The Process Of Getting Ready'
+ * but alas they don't. Attempts to e.g. mount during this period
+ * will result in device not configured due to ENXIO. The code below
+ * gives them some time to come up.
+ */
+ while ((scsi_test_unit_ready(sc_link, SCSI_SILENT) != 0) &&
+ (n != 12)) {
+ tsleep(cd, PRIBIO | PCATCH, "cdrdy", hz);
+ n++;
+ }
+
+ /* It really should be ready by now. If not, it's time to give up */
if (scsi_test_unit_ready(sc_link, SCSI_SILENT) != 0) {
SC_DEBUG(sc_link, SDEV_DB3, ("not ready\n"));
errcode = ENXIO;
goto bad;
}
+
SC_DEBUG(sc_link, SDEV_DB3, ("Device present\n"));
scsi_prevent(sc_link, PR_PREVENT, SCSI_SILENT);
/*
>Audit-Trail:
>Unformatted:
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