mei: add optional timeout to internal bus recv

Add optional timeout to internal bus recv function to
enable break out of internal flows in case of no answer from FW.
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/bus-fixup.c

@@ -266,7 +266,7 @@ static int mei_nfc_if_version(struct mei_cl *cl,
 		return -ENOMEM;
 
 	ret = 0;
-	bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length, 0);
+	bytes_recv = __mei_cl_recv(cl, (u8 *)reply, if_version_length, 0, 0);
 	if (bytes_recv < if_version_length) {
 		dev_err(bus->dev, "Could not read IF version\n");
 		ret = -EIO;

drivers/misc/mei/bus.c

@@ -116,11 +116,12 @@ ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
  * @buf: buffer to receive
  * @length: buffer length
  * @mode: io mode
+ * @timeout: recv timeout, 0 for infinite timeout
  *
  * Return: read size in bytes of < 0 on error
  */
 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
-		      unsigned int mode)
+		      unsigned int mode, unsigned long timeout)
 {
 	struct mei_device *bus;
 	struct mei_cl_cb *cb;
@@ -158,14 +159,29 @@ ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
 
 		mutex_unlock(&bus->device_lock);
 
-		if (wait_event_interruptible(cl->rx_wait,
+		if (timeout) {
+			rets = wait_event_interruptible_timeout
+					(cl->rx_wait,
+					(!list_empty(&cl->rd_completed)) ||
+					(!mei_cl_is_connected(cl)),
+					msecs_to_jiffies(timeout));
+			if (rets == 0)
+				return -ETIME;
+			if (rets < 0) {
+				if (signal_pending(current))
+					return -EINTR;
+				return -ERESTARTSYS;
+			}
+		} else {
+			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(&bus->device_lock);
 
@@ -231,7 +247,7 @@ ssize_t mei_cldev_recv_nonblock(struct mei_cl_device *cldev, u8 *buf,
 {
 	struct mei_cl *cl = cldev->cl;
 
-	return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK);
+	return __mei_cl_recv(cl, buf, length, MEI_CL_IO_RX_NONBLOCK, 0);
 }
 EXPORT_SYMBOL_GPL(mei_cldev_recv_nonblock);
 
@@ -248,7 +264,7 @@ ssize_t mei_cldev_recv(struct mei_cl_device *cldev, u8 *buf, size_t length)
 {
 	struct mei_cl *cl = cldev->cl;
 
-	return __mei_cl_recv(cl, buf, length, 0);
+	return __mei_cl_recv(cl, buf, length, 0, 0);
 }
 EXPORT_SYMBOL_GPL(mei_cldev_recv);
 

drivers/misc/mei/mei_dev.h

@@ -317,7 +317,7 @@ void mei_cl_bus_dev_fixup(struct mei_cl_device *dev);
 ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length,
 		      unsigned int mode);
 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length,
-		      unsigned int mode);
+		      unsigned int mode, unsigned long timeout);
 bool mei_cl_bus_rx_event(struct mei_cl *cl);
 bool mei_cl_bus_notify_event(struct mei_cl *cl);
 void mei_cl_bus_remove_devices(struct mei_device *bus);