spi: document odd controller reference handling (68b892f1) · Commits · 戴 / test

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 <johan@kernel.org> Signed-off-by:

Mark Brown <broonie@kernel.org>

drivers/spi/spi.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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)
		{

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