From: Niklas Schnelle schnelle@linux.ibm.com
commit b76fee1bc56c31a9d2a49592810eba30cc06d61a upstream.
A configuration request event may be stale, that is the event may reference a zdev which was already configured. This can happen when a hotplug happens during boot such that the device is discovered and configured in the initial clp_list_pci(), then after initialization we enable events and process the original configuration request which additionally still contains the old disabled function handle leading to a failure during device enablement and subsequent I/O lockout.
Fix this by restoring the check that the device to be configured is in standby which was removed in commit f606b3ef47c9 ("s390/pci: adapt events for zbus").
This check does not need serialization as we only enable the events after zPCI has fully initialized, which includes the initial clp_list_pci(), rescan only does updates and events are serialized with respect to each other.
Fixes: f606b3ef47c9 ("s390/pci: adapt events for zbus") Cc: stable@vger.kernel.org # 5.8 Reported-by: Shalini Chellathurai Saroja shalini@linux.ibm.com Tested-by: Shalini Chellathurai Saroja shalini@linux.ibm.com Acked-by: Pierre Morel pmorel@linux.ibm.com Signed-off-by: Niklas Schnelle schnelle@linux.ibm.com Signed-off-by: Heiko Carstens hca@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/s390/pci/pci_event.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -92,6 +92,9 @@ static void __zpci_event_availability(st ret = clp_add_pci_device(ccdf->fid, ccdf->fh, 1); break; } + /* the configuration request may be stale */ + if (zdev->state != ZPCI_FN_STATE_STANDBY) + break; zdev->fh = ccdf->fh; zdev->state = ZPCI_FN_STATE_CONFIGURED; ret = zpci_enable_device(zdev);