[RESEND PATCH v2] HID: Add reserved item tag for main items

[Tatsuya S <tatsuya.s2862@gmail.com>]

For main items, separate warning of reserved item tag from
warning of unknown item tag.
This comes from 6.2.2.4 Main Items of Device Class Definition
for HID 1.11 specification.

Signed-off-by: Tatsuya S <tatsuya.s2862@gmail.com>
---
V1 -> V2: Add specification location to commit message.

 drivers/hid/hid-core.c | 6 +++++-
 include/linux/hid.h    | 2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 582fd234eec7..98f557fa9e17 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -629,7 +629,11 @@ static int hid_parser_main(struct hid_parser *parser, struct hid_item *item)
 		ret = hid_add_field(parser, HID_FEATURE_REPORT, data);
 		break;
 	default:
-		hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
+		if (item->tag >= HID_MAIN_ITEM_TAG_RESERVED_MIN &&
+			item->tag <= HID_MAIN_ITEM_TAG_RESERVED_MAX)
+			hid_warn(parser->device, "reserved main item tag 0x%x\n", item->tag);
+		else
+			hid_warn(parser->device, "unknown main item tag 0x%x\n", item->tag);
 		ret = 0;
 	}
 
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 121d5b8bc867..e3894f38bd96 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -81,6 +81,8 @@ struct hid_item {
 #define HID_MAIN_ITEM_TAG_FEATURE		11
 #define HID_MAIN_ITEM_TAG_BEGIN_COLLECTION	10
 #define HID_MAIN_ITEM_TAG_END_COLLECTION	12
+#define HID_MAIN_ITEM_TAG_RESERVED_MIN		13
+#define HID_MAIN_ITEM_TAG_RESERVED_MAX		15
 
 /*
  * HID report descriptor main item contents
-- 
2.47.0