From 68b892f1fdc493d7cd4e4067596879cd097c1f62 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 30 Oct 2017 11:35:26 +0100 Subject: spi: document odd controller reference handling Document the fact that a reference to the controller is dropped as part of deregistration. This is an odd pattern as the reference is typically taken in __spi_alloc_controller() rather than spi_register_controller(). Most controller drivers gets it right these days and notably the device-managed interface relies on this behaviour. Signed-off-by: Johan Hovold Signed-off-by: Mark Brown --- drivers/spi/spi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/spi/spi.c') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6e65524cbfd9..5673cca1d1d0 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2195,7 +2195,7 @@ static void devm_spi_unregister(struct device *dev, void *res) * Context: can sleep * * Register a SPI device as with spi_register_controller() which will - * automatically be unregister + * automatically be unregistered and freed. * * Return: zero on success, else a negative error code. */ @@ -2236,6 +2236,8 @@ static int __unregister(struct device *dev, void *null) * only ones directly touching chip registers. * * This must be called from context that can sleep. + * + * Note that this function also drops a reference to the controller. */ void spi_unregister_controller(struct spi_controller *ctlr) { -- cgit