pci/hotplug/pnv-php: Improve error msg on power state change failure

When changing the slot state, if opal hits an error and tells as such
in the asynchronous reply, the warning "Wrong msg" is logged, which is
rather confusing. Instead we can reuse the better message which is
already used when we couldn't submit the asynchronous opal request
initially.
Reviewed-by: Alastair D'Silva <alastair@d-silva.org>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191121134918.7155-8-fbarrat@linux.ibm.com

drivers/pci/hotplug/pnv_php.c

@@ -336,18 +336,19 @@ int pnv_php_set_slot_power_state(struct hotplug_slot *slot,
 	ret = pnv_pci_set_power_state(php_slot->id, state, &msg);
 	if (ret > 0) {
 		if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle	||
-		    be64_to_cpu(msg.params[2]) != state			||
-		    be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) {
+		    be64_to_cpu(msg.params[2]) != state) {
 			pci_warn(php_slot->pdev, "Wrong msg (%lld, %lld, %lld)\n",
 				 be64_to_cpu(msg.params[1]),
 				 be64_to_cpu(msg.params[2]),
 				 be64_to_cpu(msg.params[3]));
 			return -ENOMSG;
 		}
+		if (be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) {
+			ret = -ENODEV;
+			goto error;
+		}
 	} else if (ret < 0) {
-		pci_warn(php_slot->pdev, "Error %d powering %s\n",
-			 ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off");
-		return ret;
+		goto error;
 	}
 
 	if (state == OPAL_PCI_SLOT_POWER_OFF || state == OPAL_PCI_SLOT_OFFLINE)
@@ -356,6 +357,11 @@ int pnv_php_set_slot_power_state(struct hotplug_slot *slot,
 		ret = pnv_php_add_devtree(php_slot);
 
 	return ret;
+
+error:
+	pci_warn(php_slot->pdev, "Error %d powering %s\n",
+		 ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off");
+	return ret;
 }
 EXPORT_SYMBOL_GPL(pnv_php_set_slot_power_state);