[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/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index f49f0e5..0a2f2ed 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -61,7 +61,7 @@
}
private->request = NULL;
memcpy(&request->irb, irb, sizeof(*irb));
- stsch(sch->schid, &sch->schib);
+ cio_update_schib(sch);
complete(&request->completion);
put_device(&sch->dev);
}
