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>
This commit is contained in:
Jason Gerecke 2015-05-21 10:44:32 -07:00 committed by Jiri Kosina
parent aef3156d72
commit 05e8fd9202

View File

@ -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;