On 29-10-17, 13:01, Johan Hovold wrote:

Remove erroneous spi_master_put() after controller deregistration which would access the already freed spi controller.

Note that spi_unregister_master() drops our only controller reference.

Fixes: ba3e67001b42 ("greybus: SPI: convert to a gpbridge driver") Cc: stable stable@vger.kernel.org # 4.9 Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Johan Hovold johan@kernel.org

---

drivers/staging/greybus/spilib.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c index e97b19148497..1e7321a1404c 100644 --- a/drivers/staging/greybus/spilib.c +++ b/drivers/staging/greybus/spilib.c @@ -544,11 +544,14 @@ int gb_spilib_master_init(struct gb_connection *connection, struct device *dev, return 0; -exit_spi_unregister:

• spi_unregister_master(master);

exit_spi_put: spi_master_put(master);

• return ret;

+exit_spi_unregister:

• spi_unregister_master(master);
• return ret;

} EXPORT_SYMBOL_GPL(gb_spilib_master_init); @@ -558,7 +561,6 @@ void gb_spilib_master_exit(struct gb_connection *connection) struct spi_master *master = gb_connection_get_data(connection); spi_unregister_master(master);

• spi_master_put(master);

} EXPORT_SYMBOL_GPL(gb_spilib_master_exit);

Acked-by: Viresh Kumar viresh.kumar@linaro.org

While looking at this I think I found another problem (I will send it as a separate patch later on) and this fixes it:

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6e65524cbfd9..af7ca751b4f7 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2261,11 +2261,11 @@ void spi_unregister_controller(struct spi_controller *ctlr) mutex_unlock(&board_lock);

dummy = device_for_each_child(&ctlr->dev, NULL, __unregister); - device_unregister(&ctlr->dev); /* free bus id */ mutex_lock(&board_lock); idr_remove(&spi_master_idr, ctlr->bus_num); mutex_unlock(&board_lock); + device_unregister(&ctlr->dev); } EXPORT_SYMBOL_GPL(spi_unregister_controller);