[S390] cio: introduce cio_update_schib
There is the chance that we get condition code 0 for a stsch but
the resulting schib is not vaild. In the current code there are
2 cases:
* we do a check for validity of the schib after stsch, but at this
time we have already stored the invaild schib in the subchannel
structure. This may lead to problems.
* we don't do a check for validity, which is not that good either.
The patch addresses both issues by introducing the stsch wrapper
cio_update_schib which performs stsch on a local schib. This schib
is only written back to the subchannel if it's valid.
side note: For some functions (chp_events) the return codes are
different now (-ENXIO vs -ENODEV) but this shouldn't do harm
since the caller doesn't check for _specific_ errors.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 868aa19..51e9421 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1350,10 +1350,7 @@
static int check_for_io_on_path(struct subchannel *sch, int mask)
{
- int cc;
-
- cc = stsch(sch->schid, &sch->schib);
- if (cc)
+ if (cio_update_schib(sch))
return 0;
if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
return 1;
@@ -1422,15 +1419,13 @@
io_subchannel_verify(sch);
break;
case CHP_OFFLINE:
- if (stsch(sch->schid, &sch->schib))
- return -ENXIO;
- if (!css_sch_is_valid(&sch->schib))
+ if (cio_update_schib(sch))
return -ENODEV;
io_subchannel_terminate_path(sch, mask);
break;
case CHP_ONLINE:
- if (stsch(sch->schid, &sch->schib))
- return -ENXIO;
+ if (cio_update_schib(sch))
+ return -ENODEV;
sch->lpm |= mask & sch->opm;
io_subchannel_verify(sch);
break;