From 525d7e73277b1d2388cdbf8e8a9177aa23ba2d7a Mon Sep 17 00:00:00 2001 From: Jason Gerecke Date: Wed, 1 Apr 2020 14:23:29 -0700 Subject: [PATCH] HID: wacom: Read HID_DG_CONTACTMAX directly for non-generic devices commit 778fbf4179991e7652e97d7f1ca1f657ef828422 upstream. We've recently switched from extracting the value of HID_DG_CONTACTMAX at a fixed offset (which may not be correct for all tablets) to injecting the report into the driver for the generic codepath to handle. Unfortunately, this change was made for *all* tablets, even those which aren't generic. Because `wacom_wac_report` ignores reports from non- generic devices, the contact count never gets initialized. Ultimately this results in the touch device itself failing to probe, and thus the loss of touch input. This commit adds back the fixed-offset extraction for non-generic devices. Link: https://github.com/linuxwacom/input-wacom/issues/155 Fixes: 184eccd40389 ("HID: wacom: generic: read HID_DG_CONTACTMAX from any feature report") Signed-off-by: Jason Gerecke Reviewed-by: Aaron Armstrong Skomra CC: stable@vger.kernel.org # 5.3+ Signed-off-by: Benjamin Tissoires Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/hid/wacom_sys.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c index 3038c975e417c..8249ff3a5a8d2 100644 --- a/drivers/hid/wacom_sys.c +++ b/drivers/hid/wacom_sys.c @@ -290,9 +290,11 @@ static void wacom_feature_mapping(struct hid_device *hdev, data[0] = field->report->id; ret = wacom_get_report(hdev, HID_FEATURE_REPORT, data, n, WAC_CMD_RETRIES); - if (ret == n) { + if (ret == n && features->type == HID_GENERIC) { ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT, data, n, 0); + } else if (ret == 2 && features->type != HID_GENERIC) { + features->touch_max = data[1]; } else { features->touch_max = 16; hid_warn(hdev, "wacom_feature_mapping: "