[PATCH net v4 1/4] net: dsa: ks8995: Add shutdown callback

[Linus Walleij <linusw@kernel.org>]

The DSA framework requires that dsa_switch_shutdown() be
called when the driver is shut down.

Make sure to also implement the mutual exclusion required
by checking the platform data pointer to be NULL in
.remove() and .shutdown().

Fixes: a7fe8b266f65 ("net: dsa: ks8995: Add basic switch set-up")
Reported-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>
---
 drivers/net/dsa/ks8995.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/net/dsa/ks8995.c b/drivers/net/dsa/ks8995.c
index 77d8b842693c..2522c9057382 100644
--- a/drivers/net/dsa/ks8995.c
+++ b/drivers/net/dsa/ks8995.c
@@ -833,11 +833,26 @@ static void ks8995_remove(struct spi_device *spi)
 {
 	struct ks8995_switch *ks = spi_get_drvdata(spi);
 
+	if (!ks)
+		return;
+
 	dsa_unregister_switch(ks->ds);
 	/* assert reset */
 	gpiod_set_value_cansleep(ks->reset_gpio, 1);
 }
 
+static void ks8995_shutdown(struct spi_device *spi)
+{
+	struct ks8995_switch *ks = spi_get_drvdata(spi);
+
+	if (!ks)
+		return;
+
+	dsa_switch_shutdown(ks->ds);
+
+	spi_set_drvdata(spi, NULL);
+}
+
 /* ------------------------------------------------------------------------ */
 static struct spi_driver ks8995_driver = {
 	.driver = {
@@ -846,6 +861,7 @@ static struct spi_driver ks8995_driver = {
 	},
 	.probe	  = ks8995_probe,
 	.remove	  = ks8995_remove,
+	.shutdown = ks8995_shutdown,
 	.id_table = ks8995_id,
 };
 

-- 
2.53.0