HID: wacom: generic: Treat serial number and related fields as unsigned

[mirror_ubuntu-bionic-kernel.git] / drivers / hid / hid-zpff.c

diff --git a/drivers/hid/hid-zpff.c b/drivers/hid/hid-zpff.c
index a29756c6ca02d064faee371143e750b19094f26c..4e7e01be99b13fcd28edc814f9d0a7425a74c1c0 100644 (file)
--- a/drivers/hid/hid-zpff.c
+++ b/drivers/hid/hid-zpff.c
@@ -66,11 +66,17 @@ static int zpff_init(struct hid_device *hid)
 {
        struct zpff_device *zpff;
        struct hid_report *report;
-       struct hid_input *hidinput = list_entry(hid->inputs.next,
-                                               struct hid_input, list);
-       struct input_dev *dev = hidinput->input;
+       struct hid_input *hidinput;
+       struct input_dev *dev;
        int i, error;
 
+       if (list_empty(&hid->inputs)) {
+               hid_err(hid, "no inputs found\n");
+               return -ENODEV;
+       }
+       hidinput = list_entry(hid->inputs.next, struct hid_input, list);
+       dev = hidinput->input;
+
        for (i = 0; i < 4; i++) {
                report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, i, 1);
                if (!report)