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authorSebastian Ott <sebott@linux.vnet.ibm.com>2014-02-05 13:36:05 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-02-06 11:21:23 +0100
commit1bc8927cc5b57c4d9198e4c4ac6b426b7c7d72c7 (patch)
tree74ddf63ee3f1aea6adb0e49a1044ee80973d89fe /drivers/s390/cio
parents390: fix kernel crash due to linkage stack instructions (diff)
downloadlinux-1bc8927cc5b57c4d9198e4c4ac6b426b7c7d72c7.tar.xz
linux-1bc8927cc5b57c4d9198e4c4ac6b426b7c7d72c7.zip
s390/cio: improve cio_commit_config
The modify subchannel wrapper cio_commit_config can fail when (unexpected) status is pending on the subchannel. Callers of cio_commit_config (that operated on enabled subchannels) needed to do error handling for that case (clear the unexpected status with test subchannel and retry). This error handling is missing in some code paths and caused online setting of devices to fail. Fix this for all callers by moving the error handling inside cio_commit_config. Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
-rw-r--r--drivers/s390/cio/cio.c40
1 files changed, 14 insertions, 26 deletions
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 88e35d85d205..8ee88c4ebd83 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -342,8 +342,9 @@ static int cio_check_config(struct subchannel *sch, struct schib *schib)
*/
int cio_commit_config(struct subchannel *sch)
{
- struct schib schib;
int ccode, retry, ret = 0;
+ struct schib schib;
+ struct irb irb;
if (stsch_err(sch->schid, &schib) || !css_sch_is_valid(&schib))
return -ENODEV;
@@ -367,7 +368,10 @@ int cio_commit_config(struct subchannel *sch)
ret = -EAGAIN;
break;
case 1: /* status pending */
- return -EBUSY;
+ ret = -EBUSY;
+ if (tsch(sch->schid, &irb))
+ return ret;
+ break;
case 2: /* busy */
udelay(100); /* allow for recovery */
ret = -EBUSY;
@@ -403,7 +407,6 @@ EXPORT_SYMBOL_GPL(cio_update_schib);
*/
int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
{
- int retry;
int ret;
CIO_TRACE_EVENT(2, "ensch");
@@ -418,20 +421,14 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
sch->config.isc = sch->isc;
sch->config.intparm = intparm;
- for (retry = 0; retry < 3; retry++) {
+ ret = cio_commit_config(sch);
+ if (ret == -EIO) {
+ /*
+ * Got a program check in msch. Try without
+ * the concurrent sense bit the next time.
+ */
+ sch->config.csense = 0;
ret = cio_commit_config(sch);
- if (ret == -EIO) {
- /*
- * Got a program check in msch. Try without
- * the concurrent sense bit the next time.
- */
- sch->config.csense = 0;
- } else if (ret == -EBUSY) {
- struct irb irb;
- if (tsch(sch->schid, &irb) != 0)
- break;
- } else
- break;
}
CIO_HEX_EVENT(2, &ret, sizeof(ret));
return ret;
@@ -444,7 +441,6 @@ EXPORT_SYMBOL_GPL(cio_enable_subchannel);
*/
int cio_disable_subchannel(struct subchannel *sch)
{
- int retry;
int ret;
CIO_TRACE_EVENT(2, "dissch");
@@ -456,16 +452,8 @@ int cio_disable_subchannel(struct subchannel *sch)
return -ENODEV;
sch->config.ena = 0;
+ ret = cio_commit_config(sch);
- for (retry = 0; retry < 3; retry++) {
- ret = cio_commit_config(sch);
- if (ret == -EBUSY) {
- struct irb irb;
- if (tsch(sch->schid, &irb) != 0)
- break;
- } else
- break;
- }
CIO_HEX_EVENT(2, &ret, sizeof(ret));
return ret;
}