Commit e24d0d39 authored Mar 31, 2014 by Benjamin Tissoires Committed by Jiri Kosina Apr 07, 2014

HID: core: do not scan constant input report



The Microsoft Surface Type/Touch Cover 2 is a fancy device which advertised
itself as a multitouch device but with constant input reports.
This way, hid_scan_report() gives the group MULTITOUCH to it, but
hid-multitouch can not handle it due to the constant collection ignored
by hid-input.

To prevent such crap in the future, and while we do not fix this particular
device, make the scan_report coherent with hid-input.c, and ignore constant
input reports.

CC: stable@vger.kernel.org # 3.12+
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

parent f3b0cbce

drivers/hid/hid-core.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -718,6 +718,9 @@ static int hid_scan_main(struct hid_parser parser, struct hid_item item)
		case HID_MAIN_ITEM_TAG_END_COLLECTION:
		break;
		case HID_MAIN_ITEM_TAG_INPUT:
		/* ignore constant inputs, they will be ignored by hid-input */
		if (data & HID_MAIN_ITEM_CONSTANT)
		break;
		for (i = 0; i < parser->local.usage_index; i++)
		hid_scan_input_usage(parser, parser->local.usage[i]);
		break;

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