From: Aaron Armstrong Skomra <skomra@xxxxxxxxx> commit 184eccd40389df29abefab88092c4ff33191fd0c upstream. In the generic code path, HID_DG_CONTACTMAX was previously only read from the second byte of report 0x23. Another report (0x82) has the HID_DG_CONTACTMAX in the higher nibble of the third byte. We should support reading the value of HID_DG_CONTACTMAX no matter what report we are reading or which position that value is in. To do this we submit the feature report as a event report using hid_report_raw_event(). Our modified finger event path records the value of HID_DG_CONTACTMAX when it sees that usage. Fixes: 8ffffd5212846 ("HID: wacom: fix timeout on probe for some wacoms") Signed-off-by: Aaron Armstrong Skomra <aaron.skomra@xxxxxxxxx> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hid/wacom_sys.c | 10 ++++++---- drivers/hid/wacom_wac.c | 4 ++++ 2 files changed, 10 insertions(+), 4 deletions(-) --- a/drivers/hid/wacom_sys.c +++ b/drivers/hid/wacom_sys.c @@ -311,14 +311,16 @@ static void wacom_feature_mapping(struct /* leave touch_max as is if predefined */ if (!features->touch_max) { /* read manually */ - data = kzalloc(2, GFP_KERNEL); + n = hid_report_len(field->report); + data = hid_alloc_report_buf(field->report, GFP_KERNEL); if (!data) break; data[0] = field->report->id; ret = wacom_get_report(hdev, HID_FEATURE_REPORT, - data, 2, WAC_CMD_RETRIES); - if (ret == 2) { - features->touch_max = data[1]; + data, n, WAC_CMD_RETRIES); + if (ret == n) { + ret = hid_report_raw_event(hdev, + HID_FEATURE_REPORT, data, n, 0); } else { features->touch_max = 16; hid_warn(hdev, "wacom_feature_mapping: " --- a/drivers/hid/wacom_wac.c +++ b/drivers/hid/wacom_wac.c @@ -2510,6 +2510,7 @@ static void wacom_wac_finger_event(struc struct wacom *wacom = hid_get_drvdata(hdev); struct wacom_wac *wacom_wac = &wacom->wacom_wac; unsigned equivalent_usage = wacom_equivalent_usage(usage->hid); + struct wacom_features *features = &wacom->wacom_wac.features; switch (equivalent_usage) { case HID_GD_X: @@ -2530,6 +2531,9 @@ static void wacom_wac_finger_event(struc case HID_DG_TIPSWITCH: wacom_wac->hid_data.tipswitch = value; break; + case HID_DG_CONTACTMAX: + features->touch_max = value; + return; }