[PATCH v2 16/33] HID: logitech-hidpp: preserve transport error codes in __hidpp_send_report()

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

__hidpp_send_report() returns -1 (-EPERM) whenever the underlying HID
transport write does not match the expected report length. This discards
genuine negative error codes returned by hid_hw_output_report() and
hid_hw_raw_request() (such as -ENODEV, -ESHUTDOWN, or -EPIPE), masking
device disconnection and transport failure from callers.

Preserve negative error codes from the transport call, and return -EIO
instead of -1 when a short write occurs.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hid-logitech-hidpp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 15fe9dcbca6c..3745d95f5bba 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -279,7 +279,7 @@ static int __hidpp_send_report(struct hid_device *hdev,
 			HID_REQ_SET_REPORT);
 	}
 
-	return ret == fields_count ? 0 : -1;
+	return ret == fields_count ? 0 : (ret < 0 ? ret : -EIO);
 }
 
 /*

-- 
2.56.0.542.g3ef89b7020-goog