[PATCH linux dev-4.7 v2] drivers/fsi: Don't scan after fsi-gpio_master unbound

[Christopher Bostic]

Check pointers prior to scanning master in the sysfs scan
file.  These get invalidated after an unbind operation.

Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
---
v2:
    Return error if invalid pointers passed in.
---
 drivers/fsi/fsi-master-gpio.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index c5f4f9c..49f3399 100644
--- a/drivers/fsi/fsi-master-gpio.c
+++ b/drivers/fsi/fsi-master-gpio.c
@@ -476,7 +476,14 @@ static ssize_t store_scan(struct device *dev,
 				const char *buf,
 				size_t count)
 {
-	struct fsi_master_gpio *master = dev_get_drvdata(dev);
+	struct fsi_master_gpio *master;
+
+	if (!dev)
+		return -EINVAL;
+
+	master = dev_get_drvdata(dev);
+	if (!master)
+		return -EINVAL;
 
 	fsi_master_gpio_init(master);
 
-- 
1.8.2.2