Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2024-12-29 17:22:07 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

s390/cio: Do not unregister the subchannel based on DNV

Browse Source 
Starting with commit 2297791c92 ("s390/cio: dont unregister
subchannel from child-drivers"), CIO does not unregister subchannels
when the attached device is invalid or unavailable. Instead, it
allows subchannels to exist without a connected device. However, if
the DNV value is 0, such as, when all the CHPIDs of a subchannel are
configured in standby state, the subchannel is unregistered, which
contradicts the current subchannel specification.

Update the logic so that subchannels are not unregistered based
on the DNV value. Also update the SCHIB information even if the
DNV bit is zero.

Suggested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Fixes: 2297791c92 ("s390/cio: dont unregister subchannel from child-drivers")
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
This commit is contained in:
Vineeth Vijayan 2024-09-23 22:16:43 +02:00 committed by Heiko Carstens
parent d6e48a01bb
commit 8c58a22968
2 changed files with 22 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/s390/cio/cio.c
View File

@ -459,10 +459,14 @@ int cio_update_schib(struct subchannel *sch)
{
struct schib schib;
if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
if (stsch(sch->schid, &schib))
return -ENODEV;
memcpy(&sch->schib, &schib, sizeof(schib));
if (!css_sch_is_valid(&schib))
return -EACCES;
return 0;
}
EXPORT_SYMBOL_GPL(cio_update_schib);

18
drivers/s390/cio/device.c
View File

@ -1387,14 +1387,18 @@ enum io_sch_action {
IO_SCH_VERIFY,
IO_SCH_DISC,
IO_SCH_NOP,
IO_SCH_ORPH_CDEV,
};
static enum io_sch_action sch_get_action(struct subchannel *sch)
{
struct ccw_device *cdev;
int rc;
cdev = sch_get_cdev(sch);
if (cio_update_schib(sch)) {
rc = cio_update_schib(sch);
if (rc == -ENODEV) {
/* Not operational. */
if (!cdev)
return IO_SCH_UNREG;
@ -1402,6 +1406,16 @@ static enum io_sch_action sch_get_action(struct subchannel *sch)
return IO_SCH_UNREG;
return IO_SCH_ORPH_UNREG;
}
/* Avoid unregistering subchannels without working device. */
if (rc == -EACCES) {
if (!cdev)
return IO_SCH_NOP;
if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
return IO_SCH_UNREG_CDEV;
return IO_SCH_ORPH_CDEV;
}
/* Operational. */
if (!cdev)
return IO_SCH_ATTACH;
@ -1471,6 +1485,7 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
rc = 0;
goto out_unlock;
case IO_SCH_ORPH_UNREG:
case IO_SCH_ORPH_CDEV:
case IO_SCH_ORPH_ATTACH:
ccw_device_set_disconnected(cdev);
break;
@ -1502,6 +1517,7 @@ static int io_subchannel_sch_event(struct subchannel *sch, int process)
/* Handle attached ccw device. */
switch (action) {
case IO_SCH_ORPH_UNREG:
case IO_SCH_ORPH_CDEV:
case IO_SCH_ORPH_ATTACH:
/* Move ccw device to orphanage. */
rc = ccw_device_move_to_orph(cdev);