From 320b29ffa0885c91e63782405c9c8a28fa013b98 Mon Sep 17 00:00:00 2001 From: Nicolas Saenz Julienne Date: Wed, 27 Mar 2019 11:18:48 +0100 Subject: HID: core: move Usage Page concatenation to Main item [ Upstream commit 58e75155009cc800005629955d3482f36a1e0eec ] As seen on some USB wireless keyboards manufactured by Primax, the HID parser was using some assumptions that are not always true. In this case it's s the fact that, inside the scope of a main item, an Usage Page will always precede an Usage. The spec is not pretty clear as 6.2.2.7 states "Any usage that follows is interpreted as a Usage ID and concatenated with the Usage Page". While 6.2.2.8 states "When the parser encounters a main item it concatenates the last declared Usage Page with a Usage to form a complete usage value." Being somewhat contradictory it was decided to match Window's implementation, which follows 6.2.2.8. In summary, the patch moves the Usage Page concatenation from the local item parsing function to the main item parsing function. Signed-off-by: Nicolas Saenz Julienne Reviewed-by: Terry Junge Signed-off-by: Benjamin Tissoires Signed-off-by: Sasha Levin --- include/linux/hid.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/hid.h b/include/linux/hid.h index 06e6e04e6c11..3656a04d764b 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -398,6 +398,7 @@ struct hid_global { struct hid_local { unsigned usage[HID_MAX_USAGES]; /* usage array */ + u8 usage_size[HID_MAX_USAGES]; /* usage size array */ unsigned collection_index[HID_MAX_USAGES]; /* collection index array */ unsigned usage_index; unsigned usage_minimum; -- cgit v1.2.3