HID: explain out-of-range check better

Extend the comment explaining the condition for discarding
out-of-range values to clarify the cases in which devices don't
provide any logical min/max.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 82130cf724e4..9aeca6023617 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1042,7 +1042,11 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
 
         /*
          * Ignore out-of-range values as per HID specification,
-         * section 5.10 and 6.2.25
+         * section 5.10 and 6.2.25.
+         *
+         * The logical_minimum < logical_maximum check is done so that we
+         * don't unintentionally discard values sent by devices which
+         * don't specify logical min and max.
          */
         if ((field->flags & HID_MAIN_ITEM_VARIABLE) &&
             (field->logical_minimum < field->logical_maximum) &&