From b493e10d75b3f60df4a6a166e5093cb24e97ea02 Mon Sep 17 00:00:00 2001
From: Linas Vepstas <linas@austin.ibm.com>
Date: Fri, 13 Apr 2007 15:34:22 -0700
Subject: [PATCH] --- yaml --- r: 53375 b: refs/heads/master c:
 da65944be2441191539f50ce71cd1f8030699be1 h: refs/heads/master i:   53373:
 beb64ea752b26f07e3332203ba30109f1eb10353   53371:
 00e3549caef6bd6db852903c287471a139629af4   53367:
 bfc0e42cb8590fb2291497183dc5c83b11972e3e   53359:
 2c5034b6dd2907c207e5f711aa3ad120c6c2093b   53343:
 c004f0b6a06feab3abac516f70b06483db52509d   53311:
 3422eb0399c8f019b898f1d0948a1164cbeafb1f   53247:
 2f024ad2cf79ba66292b55b78f462e1a38f0045d v: v3

---
 [refs]                                  |  2 +-
 trunk/drivers/pci/hotplug/rpaphp_core.c | 42 +++++++++++++++++--------
 2 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/[refs] b/[refs]
index 8ba54cba8151..a1548bdaf5a7 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8485d1a123e0d367bbcbfec36acf134e6895f39a
+refs/heads/master: da65944be2441191539f50ce71cd1f8030699be1
diff --git a/trunk/drivers/pci/hotplug/rpaphp_core.c b/trunk/drivers/pci/hotplug/rpaphp_core.c
index 75113d9e84ee..aa8d9a60d0a6 100644
--- a/trunk/drivers/pci/hotplug/rpaphp_core.c
+++ b/trunk/drivers/pci/hotplug/rpaphp_core.c
@@ -262,6 +262,14 @@ static int is_php_type(char *drc_type)
 	return 1;
 }
 
+/**
+ * is_php_dn() - return 1 if this is a hotpluggable pci slot, else 0
+ *
+ * This routine will return true only if the device node is
+ * a hotpluggable slot. This routine will return false
+ * for built-in pci slots (even when the built-in slots are
+ * dlparable.)
+ */
 static int is_php_dn(struct device_node *dn, const int **indexes,
 		const int **names, const int **types, const int **power_domains)
 {
@@ -269,24 +277,31 @@ static int is_php_dn(struct device_node *dn, const int **indexes,
 	int rc;
 
 	rc = get_children_props(dn, indexes, names, &drc_types, power_domains);
-	if (rc >= 0) {
-		if (is_php_type((char *) &drc_types[1])) {
-			*types = drc_types;
-			return 1;
-		}
-	}
+	if (rc < 0)
+		return 0;
 
-	return 0;
+	if (!is_php_type((char *) &drc_types[1]))
+		return 0;
+
+	*types = drc_types;
+	return 1;
 }
 
 /**
- * rpaphp_add_slot -- add hotplug or dlpar slot
+ * rpaphp_add_slot -- declare a hotplug slot to the hotplug subsystem.
+ * @dn device node of slot
+ *
+ * This subroutine will register a hotplugable slot with the
+ * PCI hotplug infrastructure. This routine is typicaly called
+ * during boot time, if the hotplug slots are present at boot time,
+ * or is called later, by the dlpar add code, if the slot is
+ * being dynamically added during runtime.
+ *
+ * If the device node points at an embedded (built-in) slot, this
+ * routine will just return without doing anything, since embedded
+ * slots cannot be hotplugged.
  *
- *	rpaphp not only registers PCI hotplug slots(HOTPLUG), 
- *	but also logical DR slots(EMBEDDED).
- *	HOTPLUG slot: An adapter can be physically added/removed. 
- *	EMBEDDED slot: An adapter can be logically removed/added
- *		  from/to a partition with the slot.
+ * To remove a slot, it suffices to call rpaphp_deregister_slot()
  */
 int rpaphp_add_slot(struct device_node *dn)
 {
@@ -299,6 +314,7 @@ int rpaphp_add_slot(struct device_node *dn)
 	if (!dn->name || strcmp(dn->name, "pci"))
 		return 0;
 
+	/* If this is not a hotplug slot, return without doing anything. */
 	if (!is_php_dn(dn, &indexes, &names, &types, &power_domains))
 		return 0;