Commit 61595012 authored by Dmitry Torokhov's avatar Dmitry Torokhov Committed by Benjamin Tissoires
Browse files

HID: simplify code in fetch_item() 



We can easily calculate the size of the item using arithmetic (shifts).
This allows to pull duplicated code out of the switch statement, making
it cleaner.

Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://patch.msgid.link/ZvwYbESMZ667QZqY@google.com


Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
parent f23aa4c0

drivers/hid/hid-core.c

+14 −17
Original line number Diff line number Diff line
@@ -754,35 +754,32 @@ static const u8 *fetch_item(const __u8 *start, const __u8 *end, struct hid_item 
	}



	item->format = HID_ITEM_FORMAT_SHORT;

	item->size = b & 3;

	item->size = BIT(b & 3) >> 1; /* 0, 1, 2, 3 -> 0, 1, 2, 4 */



	if (end - start < item->size)

		return NULL;



	switch (item->size) {

	case 0:

		return start;

		break;



	case 1:

		if ((end - start) < 1)

			return NULL;

		item->data.u8 = *start++;

		return start;

		item->data.u8 = *start;

		break;



	case 2:

		if ((end - start) < 2)

			return NULL;

		item->data.u16 = get_unaligned_le16(start);

		start = (__u8 *)((__le16 *)start + 1);

		return start;

		break;



	case 3:

		item->size++;

		if ((end - start) < 4)

			return NULL;

	case 4:

		item->data.u32 = get_unaligned_le32(start);

		start = (__u8 *)((__le32 *)start + 1);

		return start;

		break;



	default:

		unreachable();

	}



	return NULL;

	return start + item->size;

}



static void hid_scan_input_usage(struct hid_parser *parser, u32 usage)