drivers/fsi: Don't scan after fsi-gpio_master unbound

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

Signed-off-by Christopher Bostic <[email protected]>

---
v2:
Return error if invalid pointers passed in.

---
 drivers/fsi/fsi-master-gpio.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

drivers/fsi/fsi-master-gpio.c +8 -2

index c5f4f9c..49f3399 100644
@@ -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