HID: alps: Report an error if we receive invalid data in 't4_read_write_register()'
If the data received is not what is expected, we should return an error.
Otherwise, we return 0 or a positive value which will be interpreted as
success, but '*read_val' has not been updated.
Fixes: 73196ebe134d ("HID: alps: add support for Alps T4 Touchpad device")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-alps.c b/drivers/hid/hid-alps.c
index b1eeb48..925396f 100644
--- a/drivers/hid/hid-alps.c
+++ b/drivers/hid/hid-alps.c
@@ -219,6 +219,8 @@ static int t4_read_write_register(struct hid_device *hdev, u32 address,
goto exit_readbuf;
}
+ ret = -EINVAL;
+
if (*(u32 *)&readbuf[6] != address) {
dev_err(&hdev->dev, "read register address error (%x,%x)\n",
*(u32 *)&readbuf[6], address);