From: Tomas Winkler <tomas.winkler@intel.com>
Date: Mon, 2 Sep 2013 10:29:46 +0000 (+0300)
Subject: mei: bus: stop wait for read during cl state transition
X-Git-Tag: v3.11.4~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fcf584fd99282be126dfef1cd96f5064c4880ee7;p=thirdparty%2Fkernel%2Fstable.git

mei: bus: stop wait for read during cl state transition

commit e2b31644e999e8bfe3efce880fb32840299abf41 upstream.

Bus layer omitted check for client state transition while waiting
for read completion
The client state transition may occur for example as result
of firmware initiated reset

Add mei_cl_is_transitioning wrapper to reduce the code
repetition.:

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 9ecd49a7be1b3..99cc0b07a7131 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -295,10 +295,13 @@ int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length)
 
 	if (cl->reading_state != MEI_READ_COMPLETE &&
 	    !waitqueue_active(&cl->rx_wait)) {
+
 		mutex_unlock(&dev->device_lock);
 
 		if (wait_event_interruptible(cl->rx_wait,
-				(MEI_READ_COMPLETE == cl->reading_state))) {
+				cl->reading_state == MEI_READ_COMPLETE  ||
+				mei_cl_is_transitioning(cl))) {
+
 			if (signal_pending(current))
 				return -EINTR;
 			return -ERESTARTSYS;
diff --git a/drivers/misc/mei/client.h b/drivers/misc/mei/client.h
index 26b157d8bad5a..b1717bb7392fd 100644
--- a/drivers/misc/mei/client.h
+++ b/drivers/misc/mei/client.h
@@ -76,6 +76,12 @@ static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
 		(cl1->host_client_id == cl2->host_client_id) &&
 		(cl1->me_client_id == cl2->me_client_id);
 }
+static inline bool mei_cl_is_transitioning(struct mei_cl *cl)
+{
+	return (MEI_FILE_INITIALIZING == cl->state ||
+		MEI_FILE_DISCONNECTED == cl->state ||
+		MEI_FILE_DISCONNECTING == cl->state);
+}
 
 
 int mei_cl_flow_ctrl_creds(struct mei_cl *cl);
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 5e11b5b9b65d2..e67de232c416c 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -249,19 +249,16 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
 		mutex_unlock(&dev->device_lock);
 
 		if (wait_event_interruptible(cl->rx_wait,
-			(MEI_READ_COMPLETE == cl->reading_state ||
-			 MEI_FILE_INITIALIZING == cl->state ||
-			 MEI_FILE_DISCONNECTED == cl->state ||
-			 MEI_FILE_DISCONNECTING == cl->state))) {
+				MEI_READ_COMPLETE == cl->reading_state ||
+				mei_cl_is_transitioning(cl))) {
+
 			if (signal_pending(current))
 				return -EINTR;
 			return -ERESTARTSYS;
 		}
 
 		mutex_lock(&dev->device_lock);
-		if (MEI_FILE_INITIALIZING == cl->state ||
-		    MEI_FILE_DISCONNECTED == cl->state ||
-		    MEI_FILE_DISCONNECTING == cl->state) {
+		if (mei_cl_is_transitioning(cl)) {
 			rets = -EBUSY;
 			goto out;
 		}