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Diffstat (limited to 'drivers/s390/cio/css.c')
-rw-r--r--drivers/s390/cio/css.c18
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 2520a44fb93..4d98a0fdded 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -237,11 +237,25 @@ get_subchannel_by_schid(struct subchannel_id schid)
return dev ? to_subchannel(dev) : NULL;
}
+/**
+ * css_sch_is_valid() - check if a subchannel is valid
+ * @schib: subchannel information block for the subchannel
+ */
+int css_sch_is_valid(struct schib *schib)
+{
+ if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
+ return 0;
+ return 1;
+}
+EXPORT_SYMBOL_GPL(css_sch_is_valid);
+
static int css_get_subchannel_status(struct subchannel *sch)
{
struct schib schib;
- if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
+ if (stsch(sch->schid, &schib))
+ return CIO_GONE;
+ if (!css_sch_is_valid(&schib))
return CIO_GONE;
if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
return CIO_REVALIDATE;
@@ -349,7 +363,7 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
/* Will be done on the slow path. */
return -EAGAIN;
}
- if (stsch_err(schid, &schib) || !schib.pmcw.dnv) {
+ if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
/* Unusable - ignore. */
return 0;
}