From 2297791c92d04a154ad29ba5a073f9f627982110 Mon Sep 17 00:00:00 2001 From: Vineeth Vijayan Date: Sun, 25 Apr 2021 10:41:59 +0200 Subject: [PATCH] s390/cio: dont unregister subchannel from child-drivers The devices owned by the parent-driver (css) was getting unregistered from the io-subchannel driver is clearly a layering violation. Remove the subchannel unregistration from the child-drivers. This also means, if the device connected to the subchannel is not operational, or not accessible, the subchannel will not be unregistered. Instead the CIO layer will allow valid subchannels without any operational devices in sysfs. And the userspace tooling might need to be modified to optimally handle this new situation. Signed-off-by: Vineeth Vijayan Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens --- drivers/s390/cio/blacklist.c | 5 ++++- drivers/s390/cio/device.c | 21 ++++----------------- 2 files changed, 8 insertions(+), 18 deletions(-) diff --git a/drivers/s390/cio/blacklist.c b/drivers/s390/cio/blacklist.c index 4dd2eb634..f3c6569 100644 --- a/drivers/s390/cio/blacklist.c +++ b/drivers/s390/cio/blacklist.c @@ -262,7 +262,10 @@ static int blacklist_parse_proc_parameters(char *buf) if (strcmp("free", parm) == 0) { rc = blacklist_parse_parameters(buf, free, 0); - css_schedule_eval_all_unreg(0); + /* There could be subchannels without proper devices connected. + * evaluate all the entries + */ + css_schedule_eval_all(); } else if (strcmp("add", parm) == 0) rc = blacklist_parse_parameters(buf, add, 0); else if (strcmp("purge", parm) == 0) diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index 84f659c..dcd0680 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -867,19 +867,6 @@ out_err: wake_up(&ccw_device_init_wq); } -static void ccw_device_call_sch_unregister(struct ccw_device *cdev) -{ - struct subchannel *sch; - - /* Get subchannel reference for local processing. */ - if (!get_device(cdev->dev.parent)) - return; - sch = to_subchannel(cdev->dev.parent); - css_sch_device_unregister(sch); - /* Release subchannel reference for local processing. */ - put_device(&sch->dev); -} - /* * subchannel recognition done. Called from the state machine. */ @@ -1860,10 +1847,10 @@ static void ccw_device_todo(struct work_struct *work) css_schedule_eval(sch->schid); fallthrough; case CDEV_TODO_UNREG: - if (sch_is_pseudo_sch(sch)) - ccw_device_unregister(cdev); - else - ccw_device_call_sch_unregister(cdev); + spin_lock_irq(sch->lock); + sch_set_cdev(sch, NULL); + spin_unlock_irq(sch->lock); + ccw_device_unregister(cdev); break; default: break; -- 2.7.4