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| author |   Johan Hovold <johan@kernel.org> | 2017-10-30 11:35:26 +0100 |
|---|---|---|
| committer |   Mark Brown <broonie@kernel.org> | 2017-10-31 11:09:43 +0000 |
| commit | 68b892f1fdc493d7cd4e4067596879cd097c1f62 (patch) | |
| tree | 2239373187c97df66d42397dd922c113c8a84ffa /drivers/spi | |
| parent | Linux 4.14-rc1 (diff) | |
| download | linux-dev-68b892f1fdc493d7cd4e4067596879cd097c1f62.tar.xz linux-dev-68b892f1fdc493d7cd4e4067596879cd097c1f62.zip | |
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 <johan@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi.c | 4 |
1 files changed, 3 insertions, 1 deletions
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) { |