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Commit ba532198 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
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HID: core: do not reject devices when they declare too many usages 



Some device present proprietary collections with a usage min of 0x00 and
a usage max of 0xffff. hid-core currently reject them while most of the
time this is harmless.
Let's ignore the exceeding usages, and hope for the best.

Reported-by: default avatarSimon Wörner <mail@simon-woerner.de>
Signed-off-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.com>
parent 3eb4351a

drivers/hid/hid-core.c

+19 −0
Original line number Diff line number Diff line
@@ -427,6 +427,7 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item) 
{

	__u32 data;

	unsigned n;

	__u32 count;



	data = item_udata(item);
@@ -490,6 +491,24 @@ static int hid_parser_local(struct hid_parser *parser, struct hid_item *item) 
		if (item->size <= 2)

			data = (parser->global.usage_page << 16) + data;



		count = data - parser->local.usage_minimum;

		if (count + parser->local.usage_index >= HID_MAX_USAGES) {

			/*

			 * We do not warn if the name is not set, we are

			 * actually pre-scanning the device.

			 */

			if (dev_name(&parser->device->dev))

				hid_warn(parser->device,

					 "ignoring exceeding usage max\n");

			data = HID_MAX_USAGES - parser->local.usage_index +

				parser->local.usage_minimum - 1;

			if (data <= 0) {

				hid_err(parser->device,

					"no more usage index available\n");

				return -1;

			}

		}



		for (n = parser->local.usage_minimum; n <= data; n++)

			if (hid_add_usage(parser, n)) {

				dbg_hid("hid_add_usage failed\n");