The controller reference count is not decremented on deregistration if
the controller has been allocated using devm_spi_alloc_host/target().

Amend the kernel-doc for devm_spi_register_controller() and
spi_unregister_controller() so that it reflects this (more recent)
behaviour.

Fixes: 5e844cc37a5c ("spi: Introduce device-managed SPI controller allocation")
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/spi/spi.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 34aca18a96d8..b5e2f1e1a89e 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -3523,7 +3523,8 @@ static void devm_spi_unregister_controller(void *ctlr)
  * Context: can sleep
  *
  * Register a SPI device as with spi_register_controller() which will
- * automatically be unregistered and freed.
+ * automatically be unregistered (and freed unless it has been allocated using
+ * devm_spi_alloc_host/target()).
  *
  * Return: zero on success, else a negative error code.
  */
@@ -3557,7 +3558,8 @@ static int __unregister(struct device *dev, void *null)
  *
  * This must be called from context that can sleep.
  *
- * Note that this function also drops a reference to the controller.
+ * Note that this function also drops a reference to the controller unless it
+ * has been allocated using devm_spi_alloc_host/target().
  */
 void spi_unregister_controller(struct spi_controller *ctlr)
 {
-- 
2.52.0