[PATCH 07/17] HID: logitech-hidpp: return an error if the feature is not present

From: Benjamin Tissoires
Date: Tue Jan 17 2017 - 09:57:58 EST


Or the device just answers a valid feature '0'.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
---
drivers/hid/hid-logitech-hidpp.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 0c7144f..404b3b8 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -452,6 +452,9 @@ static int hidpp_root_get_feature(struct hidpp_device *hidpp, u16 feature,
if (ret)
return ret;

+ if (response.fap.params[0] == 0)
+ return -ENOENT;
+
*feature_index = response.fap.params[0];
*feature_type = response.fap.params[1];

--
2.9.3