From cdb912a40df8b8507ab60b3d52f9980c0ba1f44d Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 25 Dec 2008 13:39:12 +0100 Subject: [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 Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) (limited to 'drivers/s390/cio/device.c') diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index 868aa1915380..51e94212bf66 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -1350,10 +1350,7 @@ static void io_subchannel_verify(struct subchannel *sch) 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 @@ static int io_subchannel_chp_event(struct subchannel *sch, 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; -- cgit v1.2.3