Commit 05e8fd92 authored May 21, 2015 by Jason Gerecke Committed by Jiri Kosina May 21, 2015

HID: wacom: Handle failing HID_DG_CONTACTMAX requests

Hardware may not respond to a request for the HID_DG_CONTACTMAX feature and
we should be tolerant of such a failure. This is especially true when using
hid-replay where the hardware doesn't exist, but also for devices attached
to a flaky bus. This patch increases the number of allowable retries to
match other calls to 'wacom_get_report' and also provides a fallback which
forces 'touch_max = 16' (enough for any Wacom device seen so far).

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

parent aef3156d

drivers/hid/wacom_sys.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -125,9 +125,16 @@ static void wacom_feature_mapping(struct hid_device *hdev,
		break;
		data[0] = field->report->id;
		ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
		data, 2, 0);
		if (ret == 2)
		data, 2, WAC_CMD_RETRIES);
		if (ret == 2) {
		features->touch_max = data[1];
		} else {
		features->touch_max = 16;
		hid_warn(hdev, "wacom_feature_mapping: "
		"could not get HID_DG_CONTACTMAX, "
		"defaulting to %d\n",
		features->touch_max);
		}
		kfree(data);
		}
		break;