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>

3 files changed, 14 insertions, 8 deletions

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 9ecd49a7be1b..99cc0b07a713 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 cfdb144526aa..467d9dda97fa 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 053139f61086..701698de5ac7 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -262,19 +262,16 @@ 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;
                 }