Merge remote-tracking branch 'spi/fix/core' into spi-linus

drivers/spi/spi.c

@@ -370,6 +370,17 @@ static void spi_dev_set_name(struct spi_device *spi)
 		     spi->chip_select);
 }
 
+static int spi_dev_check(struct device *dev, void *data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_device *new_spi = data;
+
+	if (spi->master == new_spi->master &&
+	    spi->chip_select == new_spi->chip_select)
+		return -EBUSY;
+	return 0;
+}
+
 /**
  * spi_add_device - Add spi_device allocated with spi_alloc_device
  * @spi: spi_device to register
@@ -384,7 +395,6 @@ int spi_add_device(struct spi_device *spi)
 	static DEFINE_MUTEX(spi_add_lock);
 	struct spi_master *master = spi->master;
 	struct device *dev = master->dev.parent;
-	struct device *d;
 	int status;
 
 	/* Chipselects are numbered 0..max; validate. */
@@ -404,12 +414,10 @@ int spi_add_device(struct spi_device *spi)
 	 */
 	mutex_lock(&spi_add_lock);
 
-	d = bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev));
-	if (d != NULL) {
+	status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
+	if (status) {
 		dev_err(dev, "chipselect %d already in use\n",
 				spi->chip_select);
-		put_device(d);
-		status = -EBUSY;
 		goto done;
 	}
 
@@ -591,8 +599,10 @@ static int spi_transfer_one_message(struct spi_master *master,
 			goto out;
 		}
 
-		if (ret > 0)
+		if (ret > 0) {
+			ret = 0;
 			wait_for_completion(&master->xfer_completion);
+		}
 
 		trace_spi_transfer_stop(msg, xfer);
 
@@ -632,7 +642,7 @@ static int spi_transfer_one_message(struct spi_master *master,
  *
  * Called by SPI drivers using the core transfer_one_message()
  * implementation to notify it that the current interrupt driven
- * transfer has finised and the next one may be scheduled.
+ * transfer has finished and the next one may be scheduled.
  */
 void spi_finalize_current_transfer(struct spi_master *master)
 {
@@ -735,7 +745,9 @@ static void spi_pump_messages(struct kthread_work *work)
 	ret = master->transfer_one_message(master, master->cur_msg);
 	if (ret) {
 		dev_err(&master->dev,
-			"failed to transfer one message from queue\n");
+			"failed to transfer one message from queue: %d\n", ret);
+		master->cur_msg->status = ret;
+		spi_finalize_current_message(master);
 		return;
 	}
 }

include/linux/spi/spi.h

@@ -277,15 +277,17 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  * @unprepare_transfer_hardware: there are currently no more messages on the
  *	queue so the subsystem notifies the driver that it may relax the
  *	hardware by issuing this call
- * @set_cs: assert or deassert chip select, true to assert.  May be called
+ * @set_cs: set the logic level of the chip select line.  May be called
  *          from interrupt context.
  * @prepare_message: set up the controller to transfer a single message,
  *                   for example doing DMA mapping.  Called from threaded
  *                   context.
- * @transfer_one: transfer a single spi_transfer. When the
- *	          driver is finished with this transfer it must call
- *	          spi_finalize_current_transfer() so the subsystem can issue
- *                the next transfer
+ * @transfer_one: transfer a single spi_transfer.
+ *                  - return 0 if the transfer is finished,
+ *                  - return 1 if the transfer is still in progress. When
+ *                    the driver is finished with this transfer it must
+ *                    call spi_finalize_current_transfer() so the subsystem
+ *                    can issue the next transfer
  * @unprepare_message: undo any work done by prepare_message().
  * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS
  *	number. Any individual value may be -ENOENT for CS lines that