Merge branch 'spi-5.15' into spi-5.16

drivers/spi/spi-mux.c

@@ -137,6 +137,13 @@ static int spi_mux_probe(struct spi_device *spi)
 	priv = spi_controller_get_devdata(ctlr);
 	priv->spi = spi;
 
+	/*
+	 * Increase lockdep class as these lock are taken while the parent bus
+	 * already holds their instance's lock.
+	 */
+	lockdep_set_subclass(&ctlr->io_mutex, 1);
+	lockdep_set_subclass(&ctlr->add_lock, 1);
+
 	priv->mux = devm_mux_control_get(&spi->dev, NULL);
 	if (IS_ERR(priv->mux)) {
 		ret = dev_err_probe(&spi->dev, PTR_ERR(priv->mux),

drivers/spi/spi.c

@@ -477,12 +477,6 @@ static LIST_HEAD(spi_controller_list);
  */
 static DEFINE_MUTEX(board_lock);
 
-/*
- * Prevents addition of devices with same chip select and
- * addition of devices below an unregistering controller.
- */
-static DEFINE_MUTEX(spi_add_lock);
-
 /**
  * spi_alloc_device - Allocate a new SPI device
  * @ctlr: Controller to which device is connected
@@ -635,9 +629,9 @@ static int spi_add_device(struct spi_device *spi)
 	/* Set the bus ID string */
 	spi_dev_set_name(spi);
 
-	mutex_lock(&spi_add_lock);
+	mutex_lock(&ctlr->add_lock);
 	status = __spi_add_device(spi);
-	mutex_unlock(&spi_add_lock);
+	mutex_unlock(&ctlr->add_lock);
 	return status;
 }
 
@@ -656,7 +650,7 @@ static int spi_add_device_locked(struct spi_device *spi)
 	/* Set the bus ID string */
 	spi_dev_set_name(spi);
 
-	WARN_ON(!mutex_is_locked(&spi_add_lock));
+	WARN_ON(!mutex_is_locked(&ctlr->add_lock));
 	return __spi_add_device(spi);
 }
 
@@ -2632,6 +2626,12 @@ struct spi_controller *__spi_alloc_controller(struct device *dev,
 		return NULL;
 
 	device_initialize(&ctlr->dev);
+	INIT_LIST_HEAD(&ctlr->queue);
+	spin_lock_init(&ctlr->queue_lock);
+	spin_lock_init(&ctlr->bus_lock_spinlock);
+	mutex_init(&ctlr->bus_lock_mutex);
+	mutex_init(&ctlr->io_mutex);
+	mutex_init(&ctlr->add_lock);
 	ctlr->bus_num = -1;
 	ctlr->num_chipselect = 1;
 	ctlr->slave = slave;
@@ -2904,11 +2904,6 @@ int spi_register_controller(struct spi_controller *ctlr)
 			return id;
 		ctlr->bus_num = id;
 	}
-	INIT_LIST_HEAD(&ctlr->queue);
-	spin_lock_init(&ctlr->queue_lock);
-	spin_lock_init(&ctlr->bus_lock_spinlock);
-	mutex_init(&ctlr->bus_lock_mutex);
-	mutex_init(&ctlr->io_mutex);
 	ctlr->bus_lock_flag = 0;
 	init_completion(&ctlr->xfer_completion);
 	if (!ctlr->max_dma_len)
@@ -3045,7 +3040,7 @@ void spi_unregister_controller(struct spi_controller *ctlr)
 
 	/* Prevent addition of new devices, unregister existing ones */
 	if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
-		mutex_lock(&spi_add_lock);
+		mutex_lock(&ctlr->add_lock);
 
 	device_for_each_child(&ctlr->dev, NULL, __unregister);
 
@@ -3076,7 +3071,7 @@ void spi_unregister_controller(struct spi_controller *ctlr)
 	mutex_unlock(&board_lock);
 
 	if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
-		mutex_unlock(&spi_add_lock);
+		mutex_unlock(&ctlr->add_lock);
 }
 EXPORT_SYMBOL_GPL(spi_unregister_controller);
 

include/linux/spi/spi.h

@@ -527,6 +527,9 @@ struct spi_controller {
 	/* I/O mutex */
 	struct mutex		io_mutex;
 
+	/* Used to avoid adding the same CS twice */
+	struct mutex		add_lock;
+
 	/* lock and mutex for SPI bus locking */
 	spinlock_t		bus_lock_spinlock;
 	struct mutex		bus_lock_mutex;