From: Sebastian Ott <sebott@linux.vnet.ibm.com>
Subject: s390/pci: provide more debug information
Patch-mainline: v4.13-rc1
Git-commit: be2c36769f6340322c5367586adad6c3ce1ed51a
References: bnc#1066983, LTC#157731

Description:  PCI: fix hotplug related issues
Symptom:      After serveral cycles of hot-unplug/hotplug the affected
              function stops working or the kernel oopses.
Problem:      Hotplug notifications happen after the fact, meaning it's
              not possible to issue instructions to the function for
              cleanup purposes. Thus we never release the associated
              resources and at some point fail to allocate new ones.
Solution:     During clean up treat some errors as success (e.g. a
              function that's gone can't create an interrupt).
Reproduction: vmcp att pcif XXX to \* ;vmcp det pcif XXX #in a loop

Upstream-Description:

              s390/pci: provide more debug information

              Add some debug data to observe the lifetime of the
              architecture specific device information.

              Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
              Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
              Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>


Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 arch/s390/pci/pci.c     |    1 +
 arch/s390/pci/pci_clp.c |    5 +++--
 2 files changed, 4 insertions(+), 2 deletions(-)

--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -772,6 +772,7 @@ void pcibios_remove_bus(struct pci_bus *
 	list_del(&zdev->entry);
 	spin_unlock(&zpci_list_lock);
 
+	zpci_dbg(3, "rem fid:%x\n", zdev->fid);
 	kfree(zdev);
 }
 
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -193,12 +193,12 @@ out:
 int clp_add_pci_device(u32 fid, u32 fh, int configured)
 {
 	struct zpci_dev *zdev;
-	int rc;
+	int rc = -ENOMEM;
 
 	zpci_dbg(3, "add fid:%x, fh:%x, c:%d\n", fid, fh, configured);
 	zdev = kzalloc(sizeof(*zdev), GFP_KERNEL);
 	if (!zdev)
-		return -ENOMEM;
+		goto error;
 
 	zdev->fh = fh;
 	zdev->fid = fid;
@@ -219,6 +219,7 @@ int clp_add_pci_device(u32 fid, u32 fh,
 	return 0;
 
 error:
+	zpci_dbg(0, "add fid:%x, rc:%d\n", fid, rc);
 	kfree(zdev);
 	return rc;
 }