diff options
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 34 |
1 files changed, 29 insertions, 5 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 56035637d8f6..acc8eeed73f0 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -428,6 +428,12 @@ 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 @@ -506,7 +512,6 @@ static int spi_dev_check(struct device *dev, void *data) */ int spi_add_device(struct spi_device *spi) { - static DEFINE_MUTEX(spi_add_lock); struct spi_controller *ctlr = spi->controller; struct device *dev = ctlr->dev.parent; int status; @@ -534,6 +539,13 @@ int spi_add_device(struct spi_device *spi) goto done; } + /* Controller may unregister concurrently */ + if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && + !device_is_registered(&ctlr->dev)) { + status = -ENODEV; + goto done; + } + if (ctlr->cs_gpios) spi->cs_gpio = ctlr->cs_gpios[spi->chip_select]; @@ -1113,8 +1125,6 @@ out: if (msg->status && ctlr->handle_err) ctlr->handle_err(ctlr, msg); - spi_res_release(ctlr, msg); - spi_finalize_current_message(ctlr); return ret; @@ -1372,6 +1382,13 @@ void spi_finalize_current_message(struct spi_controller *ctlr) spi_unmap_msg(ctlr, mesg); + /* In the prepare_messages callback the spi bus has the opportunity to + * split a transfer to smaller chunks. + * Release splited transfers here since spi_map_msg is done on the + * splited transfers. + */ + spi_res_release(ctlr, mesg); + if (ctlr->cur_msg_prepared && ctlr->unprepare_message) { ret = ctlr->unprepare_message(ctlr, mesg); if (ret) { @@ -2264,7 +2281,12 @@ void spi_unregister_controller(struct spi_controller *ctlr) { struct spi_controller *found; int id = ctlr->bus_num; - int dummy; + + /* Prevent addition of new devices, unregister existing ones */ + if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) + mutex_lock(&spi_add_lock); + + device_for_each_child(&ctlr->dev, NULL, __unregister); /* First make sure that this controller was ever added */ mutex_lock(&board_lock); @@ -2278,13 +2300,15 @@ void spi_unregister_controller(struct spi_controller *ctlr) list_del(&ctlr->list); mutex_unlock(&board_lock); - dummy = device_for_each_child(&ctlr->dev, NULL, __unregister); device_unregister(&ctlr->dev); /* free bus id */ mutex_lock(&board_lock); if (found == ctlr) idr_remove(&spi_master_idr, id); mutex_unlock(&board_lock); + + if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) + mutex_unlock(&spi_add_lock); } EXPORT_SYMBOL_GPL(spi_unregister_controller); |