1 files changed, 26 insertions, 22 deletions

diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index e1bf54481fd6..9d0b7050c79a 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -182,32 +182,36 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
                 goto out;
         }
 
-        if (rets == -EBUSY &&
-            !mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, file)) {
-                rets = -ENOMEM;
-                goto out;
-        }
 
-        do {
-                mutex_unlock(&dev->device_lock);
-
-                if (wait_event_interruptible(cl->rx_wait,
-                                             (!list_empty(&cl->rd_completed)) ||
-                                             (!mei_cl_is_connected(cl)))) {
+again:
+        mutex_unlock(&dev->device_lock);
+        if (wait_event_interruptible(cl->rx_wait,
+                                     !list_empty(&cl->rd_completed) ||
+                                     !mei_cl_is_connected(cl))) {
+                if (signal_pending(current))
+                        return -EINTR;
+                return -ERESTARTSYS;
+        }
+        mutex_lock(&dev->device_lock);
 
-                        if (signal_pending(current))
-                                return -EINTR;
-                        return -ERESTARTSYS;
-                }
+        if (!mei_cl_is_connected(cl)) {
+                rets = -ENODEV;
+                goto out;
+        }
 
-                mutex_lock(&dev->device_lock);
-                if (!mei_cl_is_connected(cl)) {
-                        rets = -ENODEV;
-                        goto out;
-                }
+        cb = mei_cl_read_cb(cl, file);
+        if (!cb) {
+                /*
+                 * For amthif all the waiters are woken up,
+                 * but only fp with matching cb->fp get the cb,
+                 * the others have to return to wait on read.
+                 */
+                if (cl == &dev->iamthif_cl)
+                        goto again;
 
-                cb = mei_cl_read_cb(cl, file);
-        } while (!cb);
+                rets = 0;
+                goto out;
+        }
 
 copy_buffer:
         /* now copy the data to user space */