From: Alex Elder <elder@linaro.org>
Date: Fri, 12 Jun 2015 15:21:07 +0000 (-0500)
Subject: greybus: connection: drop unneeded gb_protocol_put() calls
X-Git-Tag: v4.9-rc1~119^2~378^2~21^2~1469
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=deb58ca8299598f81123dd92456c0cc3a9a38555;p=linux.git

greybus: connection: drop unneeded gb_protocol_put() calls

Although a connection records its protocol id when it gets
created, its protocol handler doesn't actually get assigned
until gb_connection_bind_protocol() is called.

In gb_connection_create() there are some error paths in
which a reference to the connection's protocol is released
before the protocol handler has been associated with the
connection.

Get rid of those calls.

As a result, we will never pass a null protocol pointer to
gb_protocol_put().  Add a precautionary warning in that
function in the event that ever occurs.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
---

diff --git a/drivers/staging/greybus/connection.c b/drivers/staging/greybus/connection.c
index bf5fa101e541..abd74116cf62 100644
--- a/drivers/staging/greybus/connection.c
+++ b/drivers/staging/greybus/connection.c
@@ -195,7 +195,6 @@ struct gb_connection *gb_connection_create(struct gb_bundle *bundle,
 	connection->major = major;
 	connection->minor = minor;
 	if (!gb_connection_hd_cport_id_alloc(connection)) {
-		gb_protocol_put(connection->protocol);
 		kfree(connection);
 		return NULL;
 	}
@@ -217,7 +216,6 @@ struct gb_connection *gb_connection_create(struct gb_bundle *bundle,
 		pr_err("failed to add connection device for cport 0x%04hx\n",
 			cport_id);
 		gb_connection_hd_cport_id_free(connection);
-		gb_protocol_put(connection->protocol);
 		put_device(&connection->dev);
 
 		return NULL;
@@ -264,6 +262,7 @@ void gb_connection_destroy(struct gb_connection *connection)
 
 	gb_connection_hd_cport_id_free(connection);
 	gb_protocol_put(connection->protocol);
+	connection->protocol = NULL;
 
 	device_unregister(&connection->dev);
 }
diff --git a/drivers/staging/greybus/protocol.c b/drivers/staging/greybus/protocol.c
index eed77c3f3a7f..6aebbbd585e1 100644
--- a/drivers/staging/greybus/protocol.c
+++ b/drivers/staging/greybus/protocol.c
@@ -196,7 +196,7 @@ void gb_protocol_put(struct gb_protocol *protocol)
 	u8 minor;
 	u8 protocol_count;
 
-	if (!protocol)
+	if (WARN_ON(!protocol))
 		return;
 
 	id = protocol->id;