[PATCH] spi: Add call to spi_slave_abort() function when spidev driver is released

[Lukasz Majewski]

This change is necessary for spidev devices (e.g. /dev/spidev3.0) working
in the slave mode (like NXP's dspi driver for Vybrid SoC).

When SPI HW works in this mode - the master is responsible for providing
CS and CLK signals. However, when some fault happens - like for example
distortion on SPI lines - the SPI Linux driver needs a chance to recover
from this abnormal situation and prepare itself for next (correct)
transmission.

This change doesn't pose any threat on drivers working in master mode as
spi_slave_abort() function checks if SPI slave mode is supported.

Signed-off-by: Lukasz Majewski <lukma@xxxxxxx>
Link: https://lore.kernel.org/r/20190924110547.14770-2-lukma@xxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
 drivers/spi/spidev.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index 255786f2e844..fe9ea7e55e5b 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -627,6 +627,7 @@ static int spidev_release(struct inode *inode, struct file *filp)
 		if (dofree)
 			kfree(spidev);
 	}
+	spi_slave_abort(spidev->spi);
 	mutex_unlock(&device_list_lock);
 
 	return 0;
-- 
2.20.1